System for pitch adjustment and de-icing of blades of a propeller, the system comprising a main generator with differential speed

Abstract

The invention relates to a system (10) for pitch adjustment and de-icing of blades (14) of a propeller (12), the system comprising: a first rotary drive element (20); a second rotary drive element (22); an epicyclic gear train (24) configured so that the second rotary drive element (22) is rotated at a second rotational speed, slower than the first rotational speed; an electric motor (80) used to adjust the pitch of the blades of the propeller; a de-icing device (90) for de-icing the blades; a main generator (60) with differential speed comprising a wound inductor (62) supported by the first rotary drive element and an armature (64) supported by the second rotary drive element and configured to output an AC voltage (VgAC); an AC-DC rectifier (66) configured to output a main DC voltage (VgDC) from the AC voltage (VgAC); an excitation device (52) configured to supply a DC excitation voltage (VeDC) to the wound inductor of the main generator; a supply device (40) configured to supply a DC supply voltage (Va'DC) to the excitation device (52); and a regulating unit (70, 71) configured to regulate the main DC voltage (VgDC) to a constant value by adjusting the DC supply voltage (Va'DC) supplied by the supply device to the inductor of the exciter machine.

Description

[0001] Description

[0002] Title of the invention: System for adjusting the pitch and de-icing the blades of a propeller comprising a main generator with differential speed

[0003] Technical Field

[0004] The present invention relates to the technical field of systems for jointly adjusting the pitch of the blades of an aircraft propeller and de-icing said blades. The aircraft may comprise a turboprop 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.

[0005] Prior art

[0006] Most propeller blades on turboprops or turbofans are equipped with a de-icing device using heating mats that prevent ice formation. The heating mats are traditionally powered by a brush collector device, which has many disadvantages. In particular, these brush collector devices wear out quickly and require regular maintenance. These devices are also very heavy and bulky.

[0007] Known solutions propose transferring electrical energy from the fixed reference frame to a rotating reference frame by a rotating transformer with or without brushes. However, such a rotating transformer is not satisfactory given the significant integration constraints it involves. In particular, such a rotating transformer has an imposing diameter if it is located downstream of the pitch actuation system and if it is integral with the external fixed structure of the turbomachine. It also causes difficulties in accessing the fixed support if it is located upstream of the conventional hydraulic pitch actuation system. The use of a rotating transformer also causes difficulties in routing the harnesses for powering the primary circuit of the rotating transformer in the fixed reference frame.

[0008] Furthermore, a conventional hydraulic pitch control system has a hydraulic transfer from the fixed part to the rotating part, which does not provide easy access to the fixed part on the cone side of the turbomachine. In addition, a three-phase or single-phase rotating transformer transfers the electrical power corresponding to the need, which determines its significant mass. A DC / AC energy converter of equivalent power must therefore be provided.

[0009] It may therefore be desirable to design a system that overcomes all or part of the aforementioned constraints.

[0010] Document FR3131277 describes a solution for powering the electric motor for adjusting the pitch of the blades of a propeller and the de-icing device for the blades of said propeller by means of a main generator comprising a stator carried by a fixed support and a rotor carried by a rotating support. This main generator is further associated with an exciter machine connected upstream of said generator.

[0011] The solution described in this document eliminates the need for a rotating transformer, a heavy and bulky device, as well as the DC / AC energy converters required for using a rotating transformer. In addition, the fact that such a main electric generator generates electrical power in the rotating reference of its rotor makes it possible to reduce the length of the electrical connections, grouped in power harnesses, between this generator and, respectively, the electric motor for adjusting the blade pitch and the de-icing device.

[0012] A disadvantage of the solution described in this document is that the system for powering the electric motor for adjusting the pitch of the propeller blades and the de-icing device is driven by the low rotation of the aircraft, i.e. at the rotation speed of the propeller. Also, the main generator and the excitation device that make up this power supply system are consequently large and have significant bulk and weight.

[0013] Another disadvantage of the solution described in this document is that the regulation of the voltage delivered by the main generator to meet the power required for the de-icing device involves a significant voltage variation range. Consequently, the electric motor for adjusting the pitch of the propeller blades must be sized to support a significant voltage range, which will require a significant mass. Presentation of the invention

[0014] An aim of the present invention is to propose a system for adjusting the pitch and de-icing the blades of an aircraft propeller which overcomes the aforementioned drawbacks.

[0015] To this end, the invention relates to a system for adjusting the pitch and de-icing the blades of a propeller of an aircraft, the system comprising: a first rotary drive element configured to be driven in rotation by a turbomachine of the aircraft at a first rotational speed; a second rotary drive element carrying the propeller; an epicyclic gear train comprising: an inner planetary gear secured to the first rotary drive element and configured to be driven in rotation about a main axis; at least one satellite meshed with said inner planetary gear;an outer planetary gear configured to be driven about said main axis and meshed with said at least one satellite, said second rotary drive element being integral with the outer planetary gear so that said second rotary drive element is rotated at a second rotational speed, lower than said first rotational speed, when the first rotary drive element is rotated at said first rotational speed; an electric motor comprising a stator carried by the second rotary drive element and a rotor used to adjust the pitch of the blades of the propeller of the aircraft; a device for de-icing said blades of the propeller carried by the second rotary drive element;a differential speed main generator comprising a wound inductor carried by the first rotary drive element, such that it is configured to be driven in rotation at said first rotational speed, and an armature carried by the second rotary drive element, such that it is configured to be driven in rotation at said second rotational speed, the armature being configured to deliver an alternating voltage; an alternating-direct rectifier connected to the armature of the main generator and configured to deliver a main direct voltage to the electric motor and the defrosting device, from said alternating voltage supplied by the armature of the main generator;an excitation device configured to supply a DC excitation voltage to the wound inductor of the main generator, the excitation device comprising an excitation machine comprising an inductor carried by the second rotary drive element and a wound armature carried by the first rotary drive element; a power supply device for powering the excitation device, configured to supply a DC supply voltage to the inductor of the excitation machine of the excitation device, the power supply device comprising a permanent magnet generator comprising a permanent magnet inductor carried by the first rotary drive element and an armature carried by the second drive element;and a regulating 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.;

[0016] In a non-limiting manner, the aircraft advantageously comprises a turbomachine for driving the first rotary drive element in rotation. Said turbomachine advantageously comprises 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 and the fan of a turbojet. The term "blades" covers both the blades of the propeller of a turboprop and the blades of the fan of a turbojet. The propeller of the aircraft is carried by the second rotary drive element, so that it rotates at said second rotational speed which is lower than the rotational speed of the first rotary drive element and the inner planetary gear.

[0017] The electric motor allows the orientation of the propeller blades to be adjusted around their longitudinal axes, also called blade pitch.

[0018] In a non-limiting manner, the electric motor may be a synchronous motor or an asynchronous motor. Preferably, the stator and the rotor of the electric motor rotate around the main axis. Preferably, the electric motor is configured to drive an actuation system configured to adjust the orientation of the blades of the aircraft. In a non-limiting manner, the actuation system may be electrohydraulic (EHA), comprising for example a pump, or electromechanical (EMA), comprising for example a transmission screw and a nut. These actuation systems make it possible to adjust the orientation of the blades of the propeller of the aircraft.

[0019] The stator of the electric motor is rotated by the second rotary 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 rotary drive element. In other words, the stator and the rotor of the electric motor are both rotated and are also each arranged in a separate rotating frame of reference.

[0020] The de-icing device advantageously comprises a plurality of heating mats associated with the blades of the aircraft propeller.

[0021] The epicyclic gear train advantageously comprises a planet carrier which 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 a crown.

[0022] It is understood that the first rotary drive element is configured to rotate said inner sun gear, which then rotates said outer sun gear via said satellite. Said satellite is meshed with the inner sun gear as well as with the outer sun gear.

[0023] Said epicyclic gear train is configured to transmit the rotational movement of the first rotary drive element to the second rotary drive element, while allowing a reduction in the rotational speed between these two rotary drive elements, according to a reduction ratio specific to the epicyclic gear train. The epicyclic gear train constitutes a reducer having a reduction ratio less than 1. The outer sun gear rotates at a reduced speed relative to the rotational speed of the inner sun 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 sun gear rotate.

[0024] The first rotational speed at which the first rotary drive element and therefore the inner planetary gear rotates advantageously corresponds to the rotational speed of a low-pressure turbine of the aircraft turbomachine. The first rotary drive element may comprise a first drive shaft. The second rotary drive element may comprise a second drive shaft.

[0025] The wound inductor of the main generator, the wound armature of the exciter machine and the permanent magnet inductor of the permanent magnet generator being carried by the first rotary drive element, they are linked in rotation to said first rotary drive element. They describe the same rotational movement as said first rotary drive element. They are consequently 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.

[0026] The stator of the electric motor, the de-icing device of said propeller blades, the armature of the main generator, the inductor of the exciter machine and the armature of the permanent magnet generator being carried by the second rotary drive element, they are linked in rotation to said second rotary drive element. They describe the same rotational movement as the second rotary drive element. They are consequently 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.

[0027] The assembly formed by the main generator, the excitation device and the power supply device forms a three-stage variable frequency generator (VFG).

[0028] The armature of the permanent magnet generator of the power supply device is configured to deliver an alternating voltage. The power supply device advantageously comprises a rectifier member configured to deliver a direct voltage from the alternating voltage delivered by said permanent magnet generator. Preferably, the permanent magnet generator of the power supply device is a synchronous generator.

[0029] The excitation device is configured to supply, to the wound inductor of the main generator, said direct current excitation voltage from the direct current supply voltage supplied by the power supply device.

[0030] The excitation machine of the excitation device is configured to deliver an alternating voltage. The excitation device advantageously comprises a rectifier member configured to deliver said direct current excitation voltage to the wound inductor of the main generator from the alternating voltage delivered by said excitation machine.

[0031] The excitation voltage supplied by the excitation device to the wound inductor of the main generator allows the generation of a magnetic field by the latter. Given the relative movement 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 defrosting device.

[0032] The main generator is configured to provide said alternating voltage from said direct current excitation voltage provided by the excitation device.

[0033] Preferably, the wound inductor and the armature of the main generator rotate around the main axis.

[0034] The AC-DC rectifier is configured to output a DC voltage from an AC voltage. The AC-DC rectifier is configured to provide power in a shared manner to the de-icing device and to the electric motor for adjusting the pitch of the propeller blades. Preferably, the AC-DC rectifier is of the non-controlled or passive type. Preferably, the AC-DC rectifier is carried by the second rotary drive element.

[0035] The AC-DC rectifier device is not necessarily directly connected to the defrosting device and the electric motor.

[0036] Preferably, said AC-DC rectifier comprises a rectifier member, for example an AC / DC converter. Preferably, said rectifier member comprises two output terminals and said AC-DC rectifier further comprises a filter capacitor connected between said output terminals of the rectifier member.

[0037] The main generator of the system according to the invention is said to be of differential speed, insofar as its wound inductor and its armature are both driven in rotation, at different speeds. In other words, the difference between the second rotation speed of the second rotary drive element, and therefore of the armature of the main generator, and the first rotation speed of the first rotary drive element, and therefore of the wound inductor of the main generator, constitutes the differential speed.

[0038] Also, the armature and the wound inductor of the differential speed main generator according to the invention are both driven in rotation, unlike the system of the prior art cited in which only the wound armature of the main generator is driven in rotation at low speed while the inductor is fixed because supported by the planet carrier of the epicyclic gear train. In other words, the wound inductor as well as the armature of the differential speed main generator of the system according to the invention are positioned in two rotating reference frames considered relative to a portion of the aircraft frame.

[0039] One advantage is that it allows the dimensions and therefore the bulk of the main generator to be reduced, while still having sufficient power to supply the electric motor and the propeller blade de-icing device.

[0040] The rotation speed of the wound inductor of the main generator of the system according to the invention corresponds to the drive speed of the aircraft turbomachine.

[0041] The invention also eliminates the need for a rotating transformer, which also reduces the weight and size of the system. The invention also eliminates the difficulties of routing harnesses for powering the primary circuit of a rotating transformer. Furthermore, there is no need to implement multiple DC / AC converters, which are required when a rotating transformer is used.

[0042] Furthermore, according to the invention, the regulation unit makes it possible to regulate the main DC voltage, delivered by the AC-DC rectifier and making it possible to supply 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 kept constant despite possible variations in the speed setpoint of the electric motor and therefore despite fluctuations in the energy drawn by the latter, leading to different current draws on the armature of the main generator and at the output of the AC-DC rectifier and despite different current draws.This eliminates the need to adjust the control of the defrosting device and the heating mats according to the speed setpoint of the electric motor and the electrical energy it draws.

[0043] Another advantage is that it is not necessary to size the electric motor for adjusting the blade pitch so that it can support a wide voltage range. Therefore, the weight and size of the electric motor can be reduced.

[0044] It is understood that the regulation of the main DC voltage is achieved indirectly, by adjusting the supply voltage supplied by the power supply device.

[0045] 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 which it provides.

[0046] 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 alternating 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.

[0047] The AC-DC converter is connected between the permanent magnet generator armature and the DC / DC converter. The DC / DC converter is controllable.

[0048] The DC / DC converter can be controlled in order to adjust said DC supply voltage that it delivers according to the voltage requirements, in particular at the output of the AC-DC rectifier. Preferably, said regulation unit is configured to control said DC / DC converter so as to adjust said DC supply voltage that 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 regulation unit is connected to the DC / DC converter and provides control signals to the latter.

[0049] In this embodiment, the DC / DC converter is controllable.

[0050] Advantageously, the regulation unit is configured to adjust the supply voltage delivered by the power supply device as a function of a measurement of said main DC voltage delivered by said AC-DC rectifier. The regulation unit makes it possible to control said main DC voltage. An advantage is that the regulation is all the more precise, insofar as it is carried out taking into account the voltage variations at the output of the AC-DC rectifier.

[0051] Preferably, the regulating unit comprises a measuring member configured to measure said main DC voltage.

[0052] Preferably, said regulation unit is configured to control said DC / DC converter as a function of said measurement of said main DC voltage delivered by said AC-DC rectifier. It is understood that the regulation unit is configured to adjust the DC supply voltage delivered by the DC / DC converter as a function of said measurement of the main DC voltage. This adjustment is carried out by comparing the measured main DC voltage with a reference value, and so as to make said main DC voltage tend towards this reference value.

[0053] Preferably, the system further comprises an inverter device configured to supply an alternating voltage to the stator of the electric motor from the direct voltage delivered by the alternating-direct rectifier. The inverter device makes it possible to control the frequency and amplitude of the alternating voltage supplied to the electric motor.

[0054] Preferably, the inverter device comprises a DC / AC converter, more preferably consists of a DC / AC converter.

[0055] Advantageously, the system further comprises a motor control module configured to regulate the voltage at the stator of the electric motor, based on a pitch setpoint of the blades of the propeller of the aircraft and a measurement of the orientation of the blades of the propeller of the aircraft, said motor control module being carried by the second rotary drive element. The control module advantageously makes it possible to adjust the frequency and amplitude of the alternating voltage supplied to the electric motor. The electric motor control module makes it possible to adjust the rotation speed and the direction of rotation of the rotor of the electric motor.

[0056] It is understood that the control module is arranged in a rotating frame of reference and that it rotates at said second rotation speed. One advantage is that it eliminates the need for a means of transmitting control signals between the control module and the electric motor.

[0057] Preferably, the motor control module is configured to control said inverter device, in particular in order to adjust said alternating voltage supplied by the latter to the stator of the electric motor.

[0058] Preferably, the system comprises at least one device for measuring the orientation of the blades of the propeller of the aircraft carried by the second rotary drive element and configured to deliver said measurement of the orientation of the blades of the propeller to the engine control module. The engine control module is advantageously configured to control the inverter device as a function of said measurement of the orientation of the blades of the propeller.

[0059] Said measuring device advantageously comprises a plurality of sensors, each being associated with one of the blades of the propeller. It is understood that said measuring device is driven in rotation with the second rotary drive element and is arranged in a rotating frame of reference.

[0060] Since said measuring device and the engine control module are carried by the second rotary drive element, and are therefore both arranged in a rotating frame of reference, it is not necessary to transfer the measurement from the rotating frame of reference to the fixed frame of reference. Also, it is not necessary to provide the system with means for transmitting measurement data from a sensor arranged in the rotating frame of reference to an engine control module which would be fixed relative to a portion of the aircraft frame.

[0061] Preferably, the system comprises a control device configured to generate said pitch setpoint of the blades of the propeller of the aircraft and which is fixed relative to a portion of the frame of the aircraft, the system further comprising at least one signal transfer member configured to transfer said pitch setpoint of the blades of the propeller of the aircraft from said control device to the engine control module. The signal transfer system makes it possible to transfer the setpoint signal(s) from a fixed reference point to a rotating reference point.

[0062] In fact, the signal transfer member makes it possible to transfer the setpoint signal from the control device, which is arranged in a fixed reference frame, to the motor control module which is carried by the second rotary drive element, and which is therefore arranged in a rotating reference frame.

[0063] Preferably, the system further comprises a control module for the defrosting device powered by said main direct voltage delivered by the alternating-direct rectifier and carried by the second rotary drive element.

[0064] The control module is connected to the AC-DC rectifier. The deicing device control module is used to control the deicing device in order to control the deicing of the propeller blades. The control module is used to regulate the power supplied to the deicing device and in particular to the heating mats. It is advantageously configured to selectively power the heating mats of the deicing device, preferably according to a chosen sequence. In other words, it is used to select the blades to be deiced.

[0065] Preferably, said control module is powered by the first direct 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.

[0066] Preferably, the control device is further configured to generate a defrosting setpoint. The system advantageously comprises at least one signal transfer element configured to transfer said defrosting setpoint from said control device to the control module of the defrosting device. The signal transfer element makes it possible to transmit said defrosting setpoint from the fixed reference mark to the rotating reference mark in which the control module of the defrosting device is arranged.

[0067] Advantageously, the wound armature of the excitation 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 rotary 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.

[0068] Said diode bridge is configured to deliver to the wound inductor of the main generator a direct voltage from the alternating voltage delivered by the excitation machine of the excitation device. In other words, the diode bridge is configured to rectify the alternating voltage delivered by the excitation machine. It forms a non-controlled or passive rectifier element.

[0069] 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 inductor of the main generator.

[0070] The invention also relates to an aircraft comprising at least one propeller comprising a plurality of blades, and a system for adjusting the pitch and de-icing the blades of the propeller as described above.

[0071] The aircraft advantageously comprises a turbomachine, for example a turbojet, a turbofan or a turboprop, comprising said propeller.

[0072] Brief description of the drawings

[0073] The invention will be better understood on reading the following description of an embodiment of the invention given by way of non-limiting example, with reference to the appended drawings, in which:

[0074] [Fig. 1]Figure 1 illustrates a system for adjusting the pitch and de-icing the blades of a propeller of an aircraft according to the invention; and

[0075] [Fig. 2]Figure 2 is a sectional view, centered on the propeller area, of a part of a turbomachine comprising the system according to the invention.

[0076] Description of the embodiments

[0077] The invention relates to a system for adjusting the pitch and de-icing the blades of a propeller of an aircraft, as well as to an aircraft comprising such a system.

[0078] Figure 1 shows a system 10 for adjusting the pitch and de-icing the blades of an aircraft propeller, according to the invention.

[0079] 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 comprising a plurality of blades 14. Only one of said blades 14 is illustrated in FIG. 1.

[0080] Said turbomachine 100 further comprises said system 10 for adjusting the pitch and de-icing the blades of the propeller of the aircraft, according to the invention. The system 10 comprises an electric motor 80 for adjusting the pitch of the blades 14 of the propeller 12 and a de-icing device 90 for the blades, which will be described later.

[0081] The system 10 further comprises a first rotary drive element 20 and a second rotary drive element 22 both configured to rotate about a main 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 rotated by a low-pressure turbine of the turbomachine 100, at a first rotational speed, which is a high speed.

[0082] The system 10 comprises an epicyclic gear train 24 forming a reduction device. More specifically, this epicyclic gear train 24 comprises an inner sun gear 26, a planet carrier 28, at least one planet gear 30, only one being illustrated in FIG. 1, and an outer sun gear 32. The inner sun gear 26 is rotationally connected and secured to the first rotary drive element 20. It is configured to be rotated 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 sun gear 26 and with the outer sun gear 32 and rotates relative to the planet carrier. The outer sun gear 32 is rotationally connected and secured to the second rotary drive element 22. The outer sun gear 32 rotates around the main axis X.The rotation of the first rotary drive element 20, and thus of the inner sun gear 26, at a first rotational speed causes the rotation of the outer sun gear 32, and thus 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 reduction device. The epicyclic gear set 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 rotated at different rotational speeds.The propeller 12 of the aircraft is carried by the second rotary drive element 22, so that it rotates at the second rotational speed, around the main axis X, as illustrated in FIG. 2 showing a sectional view of a part of the turbomachine 100 comprising the system 10 according to the invention, in the area of the propeller 12.

[0083] As illustrated in Figure 2, the system further comprises a power supply device 40 comprising a permanent magnet generator 42. The permanent magnet generator 42 comprises a permanent magnet inductor 44 provided with permanent magnets and an armature 46. The permanent magnet inductor 44 of the permanent magnet generator is carried by the first rotary drive element 20 and rotates at said first rotational speed. The armature 46 of the permanent magnet generator 42 is carried by the second rotary drive element 22 and rotates at said second rotational speed. The inductor 44 and the armature 46 both rotate relative to a frame portion of the aircraft, around the main axis X, and are therefore each arranged in a separate rotating frame. The armature comprises a winding.

[0084] Taking into account 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 Va AC . This first alternating voltage Va A It is three-phase.

[0085] The power supply device 40 further comprises an AC-DC converter 48 connected to the armature 46 of the permanent magnet generator 42. It forms a rectifier member configured to deliver a first DC voltage Va DC from said first alternating voltage Va AC generated by the permanent magnet generator 42.

[0086] The power supply device 40 further comprises a controllable DC / DC converter 50 configured to convert the first direct voltage Va DCdelivered by the AC-DC converter 48 into a DC supply voltage Va' DC having a different amplitude from the direct voltage it receives.

[0087] 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 of reference. 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 the second rotary drive element 22, and secured to the latter. The inductor rotates at the second rotational 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 rotation speed, which advantageously corresponds to the rotation speed of the low pressure turbine of the aircraft.

[0088] The inductor 56 and the wound armature 58 of the excitation machine both rotate relative to a portion of the aircraft frame, around the main axis X, and are therefore each arranged in a separate rotating frame.

[0089] The continuous supply voltage Va' DCdelivered by the DC / DC converter 50 of the power supply device is supplied to the inductor 56 of the excitation machine 54, for the electrical supply of the latter. The inductor 56 of the excitation machine then makes it possible to generate a magnetic field. Taking into account this magnetic field and the relative movement between the inductor 56 and the armature 58 of the excitation machine, due to the difference in rotation speed between the latter, said wound armature 58 generates an alternating excitation voltage Ve AC . This alternating excitation voltage Ve A It is three-phase.

[0090] The excitation device 52 further comprises a diode bridge 59 connected to the wound armature 58 of the excitation machine 54. It forms a rectifier member configured to deliver a continuous excitation voltage Ve DC from said alternating excitation voltage Ve ACgenerated by the excitation machine. The diode bridge 59 of the excitation device 52 is carried by the first rotary drive element 20 and rotates at the first rotational speed.

[0091] According to the invention, the system further comprises a main generator 60 with differential speed which comprises a wound inductor 62, and an armature 64. The wound inductor 62 is connected to the excitation device 52 and more precisely to the output of the diode bridge 59. The wound inductor 62 comprises at least one winding and receives the continuous excitation voltage Ve DC, so that it is configured to generate a magnetic field. The wound inductor 62 is carried by the first rotary drive element 20, and secured to the latter. Also, it rotates around the main axis X at said first rotational speed of the first rotary drive element 20, corresponding here to the rotational speed of the low-pressure turbine of the aircraft. The armature 64 is carried by the second rotary drive element 22. Also, it is configured to rotate at said 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 rotated.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.

[0092] Taking into account the relative rotational movement 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 Vg AC which is used to power the electric motor 80 and the defrosting device 90 which will be described later. This alternating voltage Vg AC is three-phase here.

[0093] The assembly composed of the power supply device 40, the excitation device 52 and the main generator 60 forms a three-stage variable frequency generator (VFG).

[0094] The system 10 further comprises an AC-DC rectifier 66 electrically connected to the armature 64 of the main generator 60. It is constituted here by an AC / DC converter 68 forming a rectifier member 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 Vg DC from the alternating voltage Vg AC supplied by the main generator 60. The AC-DC rectifier 66 is carried by the second rotary drive element 22 and is arranged in the rotating reference frame.

[0095] The de-icing device 90 comprises a plurality of heating mats, each being associated with one of the blades 14 of the propeller 12 of the aircraft. The system 10 further comprises a control module 94 of 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.

[0096] More specifically, the control module 94 comprises a plurality of switches and is configured to selectively control the heating mats of the defrosting device 90 according to a chosen sequence, from the main DC voltage Vg DC supplied by the AC-DC rectifier 66. The control module 94 makes it possible to select the blades to be defrosted. The control module 94 is configured to control the defrosting device according to a defrosting setpoint C2.

[0097] According to the invention, the system 10 also comprises a regulation unit 70, 71 configured to regulate said direct voltage Vg DC supplied by said AC-DC rectifier 66 at a constant value. Said regulation unit 70,71 operates a servocontrol of said DC voltage Vg DC in order to keep it constant. To do this, the regulation unit 70,71 is configured to adjust the DC supply voltage Va' DC supplied by the DC / DC converter 50 of the power supply device by controlling said DC / DC converter 50 of the power supply device 40, as a function of a measurement of said main DC voltage Vg DC delivered by said AC-DC rectifier 66, in order to maintain the main DC voltage Vg DC constant. The control of the DC / DC converter 50 is carried out based on a measurement of the main DC voltage Vg DCdelivered by said AC-DC rectifier 66. The regulation unit comprises a measuring member 70 of the main DC voltage Vg DC delivered by said AC-DC rectifier 66 and a control member 71 configured to control the DC / DC converter 50, from said measurement of the main DC voltage Vg DC .

[0098] The regulating unit 70, 71 is also carried by the second rotary drive element 22 and is arranged in the rotary reference frame.

[0099] The system 10 further comprises an inverter 72 connected to the AC-DC rectifier 66. The inverter 72 is configured to provide an AC voltage V m to the stator 82 of the electric motor from the direct voltage Vg DCsupplied by said AC-DC rectifier 66. The inverter 72 is also carried by the second rotary drive element 22 and arranged in the rotating frame. The assembly formed by the AC-DC rectifier 66 and the inverter 72 makes it possible to adjust the frequency and amplitude of the AC voltage V m supplied to the electric motor 80. The system comprises a device 86 for measuring the orientation of the blades 14 of the propeller 12 of the aircraft. This measuring device 86 comprises a plurality of sensors associated with the blades 14 of the propeller. The measuring device 86 is carried by the second rotary drive element 22. It is configured to deliver a measurement m of the orientation of the blades of the propeller, considered along the longitudinal axis of said blades.

[0100] The system further comprises 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 V m powering the stator 82 of the electric motor, from a pitch setpoint Ci of the blades 14 of the propeller 12 of the aircraft and the measurement m of the orientation of the blades of the propeller of the aircraft provided by the measuring device 86. Said control module 74 of the electric motor 80 is carried by the second rotary drive element 22 and rotates at said second rotational speed. It is arranged in the rotating reference frame.

[0101] The system comprises a control device 88 configured to generate said pitch setpoint Ci of the blades 14 of the propeller 12. This control device 88 is fixed relative to a portion of the aircraft frame and is therefore arranged in the fixed frame. The system 10 further comprises a signal transfer member 96 configured to transfer said pitch setpoint Ci of the blades from said control device 88 to the control module 74 of the engine 80. In other words, the transfer member makes it possible to transfer the setpoint signal Ci from the fixed frame into the rotating frame.

[0102] The control device 88 is further configured to generate said defrosting setpoint C2, intended for the control module 94 of the defrosting device 90, which is used to control the heating mats. The system 10 further comprises 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 makes it possible to transfer the defrosting setpoint signal C2 from the fixed reference mark to the rotating reference mark.

[0103] The stator 82 of the electric motor 80 is carried by the second rotary drive element 22 so that it is arranged in the rotating frame of reference. Said stator 82 rotates about the main axis X, at said second rotational speed, corresponding to the rotational speed of the propeller. The electric motor further comprises a rotor 84 coupled to the stator 82 and driven in rotation about the main axis X when the motor is powered.

[0104] The system further comprises an actuation system 16 configured to adjust the orientation of the blades of the propeller 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 movement of the rotor 84 into a translational movement of a jack (electrohydraulic system) or a nut (electromechanical system). This translational movement is then converted into a rotational movement of the blades 14 of the propeller 12 via a connecting rod and crank mechanism 18.

Claims

Claims 1. 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 at a first rotational speed; a second rotary drive element (22) carrying the propeller (12); an epicyclic gear train (24) comprising: an inner sun gear (26) secured to the first rotary drive element (20) and configured to be driven in rotation about a main axis; at least one satellite (30) meshed with said inner sun gear;an outer planetary gear (32) configured to be driven about said main axis and meshed with said at least one satellite, said second rotary drive element (22) being integral with the outer planetary gear so that said second rotary drive element (22) is rotated at a second rotational speed, lower than said first rotational speed, when the first rotary drive element is rotated at said first rotational speed; an electric motor (80) comprising a stator (82) carried by the second rotary drive element and a rotor (84) used to adjust the pitch of the blades of the propeller of the aircraft; a de-icing device (90) for said blades of the propeller carried by the second rotary drive element;a differential speed main generator (60) comprising a wound inductor (62) carried by the first rotary drive element, such that it is configured to be driven in rotation at said first rotational speed, and an armature (64) carried by the second rotary drive element, such that it is configured to be driven in rotation at said second rotational speed, the armature being configured to deliver an alternating voltage (Vg; AC ); an AC-DC rectifier (66) connected to the armature of the main generator and configured to deliver a main DC voltage (Vg DC ) to the electric motor (80) and the defrosting device (90), from said alternating voltage (Vg AC ) supplied by the armature of the main generator; an excitation device (52) configured to supply a continuous excitation voltage (Ve DC) to the wound inductor of the main generator, the excitation device comprising an excitation 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 powering the excitation device, configured to provide a continuous power supply voltage (Va' DC ) to the inductor (56) of the excitation 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 rotary 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 (Vg DC) delivered by said AC-DC rectifier (66) at a constant value, by adjusting the DC supply voltage (Va' DC ) supplied by the power supply device to the inductor of the exciter machine.

2. System according to claim 1, in which the armature (46) of the permanent magnet generator (42) is configured to deliver a first alternating voltage (Va AC ), 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 DC voltage (Va DC ) from said first alternating voltage (Va AC ); and a DC / DC converter (50) carried by the second rotary drive element (22) and configured to deliver said direct supply voltage (Va' DC ) from the first direct voltage (Va DC) delivered by the AC-DC converter.

3. System according to claim 2, wherein said regulation unit (70,71) is configured to control said DC / DC converter (50) so as to adjust said direct supply voltage (Va' DC ) which it delivers, in order to regulate said main direct voltage (Vg DC ) delivered by said AC-DC rectifier (66) at a constant value.

4. System according to any one of claims 1 to 3, in which the regulation unit (70,71) is configured to adjust the direct current supply voltage (Va' DC ) delivered by the power supply device based on a measurement of said main DC voltage (Vg DC ) delivered by said AC-DC rectifier (66).

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

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

7. System according to one of claims 1 to 6, further comprising a control module (74) of the motor (80) configured to regulate the voltage (V m) to the stator (82) of the electric motor, from a pitch setpoint (Ci) 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 (V m ) 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 (86) 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 blades of the propeller to the control module (74) of the engine (80).

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

11. System according to any one of claims 1 to 10, further comprising a control module (94) of the defrosting device (90) powered by said main direct voltage (Vg DC ) delivered by the AC-DC rectifier (66) and carried by the second rotary drive element (22).

12. System according to any one of claims 1 to 11, in which the wound armature (58) of the excitation machine (54) of the excitation device (52) is configured to deliver an alternating excitation voltage (Ve AC ), 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 continuous excitation voltage (Ve DC ) 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 adjusting the pitch and de-icing the blades of the propeller according to any one of claims 1 to 12.

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