System for adjusting the pitch of and de-icing the blades of a propeller of an aircraft comprising a rotary transformer

Abstract

The invention relates to a system (10) for adjusting the pitch of and de-icing the blades (14) of a propeller (12) of an aircraft comprising a rotary drive element (20); an electric motor (80); a device (90) for de-icing the blades; an inverter device (46) delivering a primary AC voltage (VpAC); a rotary transformer (40) comprising a primary circuit (42) receiving the primary AC voltage (VpAC) and a secondary circuit (44) delivering a secondary AC voltage (VsAC); a rectifying device (52) delivering a main DC voltage (VgDC) from the secondary AC voltage; a DC / AC inverter module (72) configured to supply an AC voltage (Vm) to the stator (82) of the electric motor from the main DC voltage (VgDC); a device (91) for controlling the de-icing device (90) powered by the main DC voltage (VgDC); and a regulating unit (60, 60', 60'') configured to maintain the main DC voltage at a constant value.

Description

[0001]Description Title of the invention: System for adjusting the pitch and de-icing the blades of an aircraft propeller comprising a rotating transformer Technical Field The present invention relates to a system for jointly adjusting the pitch of the blades of an aircraft propeller and de-icing said blades, for example by means of heating mats associated with the blades. The aircraft may comprise a turbofan or turbojet, in which case the propeller is also called a fan, or alternatively a turboprop. The invention also relates to an aircraft comprising such a system. Prior art Systems are known comprising an electric motor for adjusting the pitch of the fan blades of a turbofan or the propeller blades of a turboprop, as well as a device for de-icing these blades. Most of the propeller blades fitted to turboprops or turbofans are equipped with a de-icing system using heating mats which prevent the formationice. Their power supply is provided by a brush collector device which presents many problems: - significant wear leading to regular maintenance; - a heavy and bulky device. Current solutions propose transferring the electrical energy from the fixed reference to the rotating reference by a rotating transformer with or without brushes. This solution, however, constitutes a major drawback due to its addition and its integration constraints such as: - an imposing diameter of the rotating transformer if it is located downstream of the pitch actuation system and if it is integral with the fixed structure of the turbomachine; - difficulties in accessing the fixed support if it is located upstream of the conventional hydraulic pitch actuation system; - difficulties in routing the harnesses for powering the primary circuit of the rotating transformer in the fixed reference. Furthermore, a hydraulic pitch setting systemThe conventional 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, the 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. It may therefore be desirable to design a system that overcomes all or part of the aforementioned constraints. Some systems provide for jointly powering the electric motor for adjusting the blade pitch and the blade de-icing device using a shared generator. A disadvantage is that driving such a generator at low speeds is complex and requires sizing the generator accordingly, significantly increasing its size. Other systems provide for jointly powering the electric motor for adjusting the blade pitch and thede-icing device via a rotating transformer for transferring electrical energy from an aircraft power source, arranged in a fixed reference frame of the aircraft, to said electric motor and said de-icing device. Document FR3131277 describes such a solution for powering the electric motor and the de-icing device of such a system via a rotating transformer. This transformer comprises a primary circuit connected to an electrical power source and a secondary circuit connected to said electric motor and to the de-icing device. The secondary circuit delivers a secondary alternating voltage to power both the electric motor and the de-icing device. This document provides for controlling the voltage of the primary circuit of the transformer, and therefore indirectly said secondary alternating voltage, as a function of propeller blade orientation measurements. AThe disadvantage of the solution described in this document is that each time the rotation speed setpoint of the electric motor varies, the electric motor draws a different amount of energy from the secondary circuit of the transformer, which induces different current draws. This has the consequence of varying the said secondary alternating voltage delivered by the transformer. In other words, this secondary alternating voltage is likely to vary and is dependent on the operation of the electric motor. As a result, the secondary alternating voltage may prove insufficient to correctly power the defrosting device. In particular, the power drawn by the defrosting device, and in particular by its heating mats, may be impacted, which leads to having to adjust the control of the defrosting device and said heating mats according to the energy resources available to it. If, on the other hand, the control of the defrosting system is adapteddefrosting as needed, the impact will be localized at the level of the pitch control device. Indeed, the regulation of the voltage delivered by the rotating transformer to respect the power required for the defrosting system involves a significant voltage variation range. The electric motor of the pitch control device will have to be sized to support a significant voltage range which will condition a significant mass. Statement of the invention An aim of the present invention is to propose a system for adjusting the pitch and defrosting the blades of a propeller of an aircraft which overcomes the aforementioned drawbacks. To do this, the invention relates to a system for adjusting the pitch and defrosting the blades of a propeller of an aircraft comprising an electrical power source delivering a constant direct voltage, the system comprising: - a rotary drive element configured to be rotated by a turbine of the aircraft; - a motorelectrical system comprising a stator rotatably connected to said rotary drive element and a rotor pivoting relative to the stator and used to adjust the pitch of the blades of the propeller of the aircraft; - a device for de-icing said propeller blades rotatably connected to said rotary drive element; - an inverter device configured to be connected to the electrical power source and to deliver a primary alternating voltage from the constant direct voltage delivered by said electrical power source; - a rotating transformer comprising a primary circuit fixed relative to a portion of the aircraft frame and connected to the inverter device so that it receives the primary alternating voltage, and a secondary circuit rotatably connected to said rotary drive element and delivering a secondary alternating voltage; - a rectifier device connected to the secondary circuit and configured to deliver a main direct voltage fromsaid secondary alternating voltage supplied by said secondary circuit, for supplying electrical energy to the electric motor and the de-icing device; - a DC / AC inverter module rotatably connected to said rotary drive element and configured to supply an alternating voltage to said stator of the electric motor from the main direct voltage supplied by the rectifier device; - a device for controlling the de-icing device powered by said main direct voltage and rotatably connected to the rotary drive element; and - a regulation unit configured to maintain said main direct voltage at a constant value. In a non-limiting manner, the aircraft advantageously comprises a turbomachine comprising said system according to the invention. 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 or turbofan. The term "blades" covers both the blades of the propeller of a turboprop and the blades of the fan of a turbojet or turbofan. Preferably, the propeller of the aircraft is rotationally connected to said rotary drive element, so that it rotates at the same rotational speed as the latter. The propeller is advantageously carried by the rotary drive element. The electrical power source is advantageously a DC bus of the aircraft. In a non-limiting manner, said electrical power source may be a continuous electrical power supply network of the aircraft. This electrical power source is advantageously fixed relative to a portion of the aircraft frame and is therefore arranged in the fixed frame. The rotary drive element is configured to rotate around a main axis. The training elementrotary drive element may comprise a drive shaft. The rotary drive element is advantageously driven in rotation by said turbine of the aircraft, via a reduction device. Also, it rotates at a rotational speed lower than the rotational speed of this turbine. The rotary drive element is advantageously driven in rotation by a low-pressure turbine of a turbomachine of the aircraft. The rotary drive element defines a rotating reference frame considered in opposition to a fixed reference frame corresponding to the reference frame of a portion of the aircraft frame. By rotationally linked, it is meant that the secondary circuit of the transformer, the de-icing device and the stator of the electric motor describe the same rotational movement as said rotary drive element. They rotate at the same rotational speed as this rotary drive element. Preferably, the secondary circuit of the transformer, the de-icing device and / or the stator of theelectric motor are carried by said rotary drive element, more preferably are integral with said rotary drive element. The rotary drive element advantageously forms a rotary support for the secondary circuit, the de-icing device and the stator of the electric motor. The inverter device makes it possible to supply an alternating voltage to the primary circuit of the rotating transformer. The primary circuit receives the primary alternating voltage at its terminals. The inverter device is advantageously connected between the electrical power source and the primary circuit of the transformer. The inverter device is advantageously fixed relative to a portion of the aircraft frame. It is therefore advantageously arranged in a fixed frame. In a non-limiting manner, the inverter device may be passive or controlled. The inverter device advantageously comprises an inverter and a capacitor connected between the input terminals of said inverter. Saidcapacitor advantageously has at its terminals the constant direct voltage delivered by the electrical power source. The secondary circuit of the rotating transformer has said secondary alternating voltage at its terminals. The de-icing device advantageously comprises a plurality of heating mats associated with the blades of the aircraft propeller and making it possible to remove ice therefrom. The heating mats can advantageously be controlled selectively, for example by means of switches. The de-icing device is arranged in the rotating frame. The de-icing device is electrically powered via the de-icing device control device, via the rotating transformer and the rectifier device. Said de-icing device control device is rotatably connected, preferably carried, by the rotating drive element. It is advantageously arranged in the rotating frame. The control device isadvantageously connected to the rectifier device. It is advantageously connected between the rectifier device and the de-icing device. The de-icing device control device makes it possible to control the de-icing device in order to control the de-icing of the propeller blades. The control device makes it possible to regulate the power supplied to the de-icing device and in particular to the heating mats. It is advantageously configured to selectively supply heating mats of the de-icing device. In other words, it makes it possible to select the blades to be de-iced. The voltage required to supply the heating mats of the de-icing device is advantageously adjusted by controlling the de-icing device control device. Preferably, said DC / AC inverter module is connected between the rectifier device and the stator of the electric motor. The combination of the rectifier device and the DC / AC inverter module makes it possible to control thefrequency and amplitude of the alternating voltage supplied to the electric motor. Preferably, said DC / AC inverter module comprises a DC / AC converter. Preferably, the electric motor comprises said DC / AC inverter module. The electric motor makes it possible to adjust the orientation of the propeller blades considered around their longitudinal axes, also called blade pitch. 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 around which the rotary drive element rotates. Preferably, the electric motor is configured to drive an actuation system configured to adjust the orientation of the aircraft blades. 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 anut. These actuation systems allow the orientation of the aircraft propeller blades to be adjusted. The rotating transformer is advantageously a low radius transformer. It is configured to transfer electrical energy from the electrical power source to the electric motor and said de-icing device. The primary circuit of the rotating transformer advantageously comprises at least one winding. The primary circuit is arranged in the fixed frame of reference. The secondary circuit of the rotating transformer advantageously comprises at least one winding. The secondary circuit of the rotating transformer is rotated by the rotating drive element and is advantageously carried by the latter. The secondary circuit is arranged in the rotating frame of reference. The secondary circuit of the rotating transformer rotates relative to the primary circuit. The primary circuit is advantageously carried by a fixed support element. The rectifier deviceconnected to the secondary circuit of the transformer is advantageously linked in rotation to the rotary drive element. It is therefore advantageously arranged in the rotating frame of reference. Preferably, the rectifier device comprises a rectifier member and a filter capacitor connected between the output terminals of the rectifier member. Said main DC voltage is then the voltage across said filter capacitor. According to the invention, the rotating transformer is shared for the electrical supply of said electric motor and said defrosting device. Similarly, said rectifier device is also shared for the electrical supply of said electric motor and said defrosting device. The main DC voltage delivered by the rectifier device is supplied jointly to the control device of the defrosting device and to said DC / AC inverter module. The regulation unit of the system according to the invention makes it possible to regulate the voltagemain DC voltage for supplying the electric motor and the defrosting device so as to maintain it at a constant value. Without departing from the scope of the invention, this regulation can be carried out either directly by directly regulating said main DC voltage, or indirectly by regulating, for example, the primary AC voltage of the primary circuit of the transformer. The regulation unit of the system according to the invention makes it possible to control the main DC voltage at a constant value, for supplying the electric motor and the defrosting device. The regulation unit of the system according to the invention makes it possible to regulate said main DC voltage at a constant value, 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 secondary circuit of the rotating transformer and at the output of therectifier device and despite different current draws. Thanks to the invention, said main DC voltage is therefore kept constant and regular. It is therefore not necessary to adjust the control of the defrosting device and said heating mats according to the speed setpoint of the electric motor and the electrical energy it draws. It is therefore not necessary to size the electric motor for adjusting the pitch of the blades so that it can support a large voltage range. Therefore, the weight and size of the electric motor can be reduced. In other words, according to the invention, the regulation of the main DC voltage supplied to the electric motor and to the defrosting device is independent of the control of the electric motor. The control of the electric motor can be carried out by means of a control unit independent of said regulation unit. Preferably, the regulation unit is configured to regulate saidmain DC voltage delivered by the rectifier device or said primary AC voltage delivered by the inverter device from a measurement of one or the other of the latter, so as to maintain said main DC voltage at a constant value. An advantage is that this regulation is carried out from a voltage measurement taken upstream of the rotating transformer, namely a measurement of the main DC voltage, or downstream of the rotating transformer, namely a measurement of the primary AC voltage. The regulation of the main DC voltage to a constant value is carried out by taking into account the voltage variations upstream or downstream of the rotating transformer, by measuring these voltages. The regulation unit makes it possible to control the main DC voltage to a constant value. It is understood here again that the regulation unit is configured to maintain said main DC voltage at a constant value either in adirectly by directly regulating the latter, or indirectly by regulating the primary alternating voltage of the primary circuit of the transformer. According to a first advantageous variant, said regulation unit is configured to control said rectifier device so as to regulate the main direct voltage delivered by the rectifier device according to a measurement of said main direct voltage, so as to maintain said main direct voltage at a constant value. In this embodiment, the regulation unit makes it possible to directly control the main direct voltage, which is used to supply the electric motor and the defrosting device, from a measurement of the latter. One advantage is to regulate said main direct voltage delivered by the rectifier device all the more precisely to a constant value. Another advantage is to make it possible to arrange the regulation unit entirely in the rotating reference frame and toconnect it in rotation to the rotary drive element. The inverter device advantageously comprises a fixed duty cycle inverter. Advantageously, said regulation unit comprises a control member configured to control said rectifier device and a measuring member communicating with the control member and configured to measure said main DC voltage delivered by the rectifier device, the control member and the measuring member being connected in rotation to said rotary drive element. The measuring member is configured to transmit to the control member said measurement of the main DC voltage. The control member is configured to control the rectifier device as a function of said measurement of the main DC voltage. The control member and the measuring member are connected in rotation with the rectifier device, the secondary circuit of the rotating transformer, and the stator of the electric motor. An interest is toto dispense with a signal transfer means between the fixed reference mark and the rotating reference mark for the transmission of measurement data between the measuring member and the control member, insofar as the latter are both arranged in said rotating reference mark and can communicate in this reference mark. According to a second advantageous variant, the regulation unit is configured to control said inverter device so as to regulate the primary alternating voltage delivered by the inverter device from a measurement of the main direct voltage delivered by the rectifier device. In this variant, the main direct voltage delivered by the rectifier device is indirectly controlled, by regulating the primary alternating voltage delivered by the inverter device. The voltage regulation is however particularly precise insofar as it is carried out from a measurement of said main direct voltage. One advantage is to allowarranging a control member of the regulation unit in the fixed frame. In this embodiment, the inverter device is controlled. In a non-limiting manner, the rectifier device is advantageously passive. Preferably, said regulation unit comprises a control member configured to control said inverter device and a measuring member communicating with the control member and configured to measure said main DC voltage delivered by the rectifier device, the control member being fixed relative to a portion of the aircraft frame while the measuring member is rotationally connected to said rotary drive element. It is understood that the control member is arranged in a fixed frame while the measuring member is arranged in a rotating frame. An advantage of arranging the control member in the fixed frame is to improve its performance and to avoid control alterations that may occur with a control member arrangedin the rotating reference frame. In addition, this configuration makes it possible to dispense with the use of an additional transmission module for transmitting information from engine computers located in the fixed part to said control member. The measuring member is linked in rotation to the rectifier device, to the secondary circuit of the transformer and to the stator of the electric motor. The measuring member is configured to transmit to the control member said measurement of the main DC voltage. The regulation unit advantageously comprises a signal transfer member configured to transfer the measurement signals from the measuring member to the control member. It is understood that the signal transfer member makes it possible to transfer the measurement signals from the rotating reference frame to the fixed reference frame. The control member is configured to control the inverter device as a function of said measurement of the main DC voltage. According to a thirdadvantageous variant, the regulation unit is configured to control said inverter device so as to regulate the primary alternating voltage delivered by the inverter device from a measurement of said primary alternating voltage delivered by the inverter device, so as to maintain said main direct voltage at a constant value. In this third variant, the main direct voltage delivered by the rectifier device is indirectly controlled, by regulating the primary alternating voltage delivered by the inverter device. Indeed, the main direct voltage is an image of said primary alternating voltage. This embodiment makes it possible to fix the entire regulation unit relative to the frame of the aircraft and therefore to arrange it in the fixed reference frame. In this embodiment, the rectifier device is passive. Advantageously, said regulation unit comprises a control member configured to control saidinverter device and a measuring member communicating with the control member and configured to measure said primary alternating voltage delivered by the inverter device, the control member and the measuring member being fixed relative to a portion of the aircraft frame. The control member and the measuring member are arranged in the fixed frame, which makes it possible to dispense with a signal transfer member for transferring the measurement signals from the rotating frame to the fixed frame. Furthermore, an advantage of arranging the control member in the fixed frame is to improve its performance and to avoid control alterations that may occur with a control member arranged in the rotating frame. Furthermore, this configuration makes it possible to dispense with the use of an additional transmission module for transmitting information from engine computers located in the fixed part to said control member. Furthermore, the arrangement ofthe measuring member in the fixed reference frame also improves the accuracy of the measurements it allows to be made. Preferably, the control device of the deicing device comprises a DC / DC converter configured to deliver a deicing DC voltage from said main DC voltage and a control module receiving said deicing DC voltage and configured to distribute the power to the deicing device. The control module and the DC / DC converter are linked in rotation, preferably carried, by the rotary drive element. They are advantageously arranged in the rotating reference frame. The control module of the control device is advantageously configured to control the successive power supply of the propeller blades. The control module is advantageously configured to selectively control and power the heating mats of the deicing device, advantageously according to a chosen sequence. In other words, it allowsselect the blades to be defrosted. The control module is advantageously configured to control the defrosting device according to a defrosting setpoint. The control module advantageously comprises at least one switch for selecting the heating mats to be powered. The voltage required to power the heating mats of the defrosting device is advantageously adjusted by controlling the DC / DC converter of the defrosting device control device. Preferably, but not limited to, the DC / DC converter and the control module of the defrosting device control device are both connected to the rectifier device. Preferably, the system comprises a control device configured to generate a defrosting setpoint for the defrosting device control device, preferably for the control module of said control device. The control device is preferably fixedrelative to a portion of the aircraft frame and is therefore arranged in the fixed frame. The system advantageously comprises at least one signal transfer element configured to transfer said deicing instruction from said control device to the control device of the deicing device. The signal transfer element makes it possible to transmit said deicing instruction from the fixed frame to the rotating frame in which the control device of the deicing device is arranged. Preferably, the system further comprises an electric motor control module configured to regulate the voltage to the stator of the electric motor, from a pitch instruction 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 rotationally linked to said rotary drive element. The motor control module is arranged in the rotating frame. Also, it is notnecessary to provide an additional module for transmitting control signals between the control module and the electric motor. The control module advantageously makes it possible to adjust the frequency and amplitude of the alternating voltage supplied to the electric motor. The control module of the electric motor makes it possible to adjust the rotation speed and the direction of rotation of the rotor of the electric motor. Preferably, the system comprises a device for measuring the orientation of the blades of the propeller of the aircraft which is linked in rotation to the rotary drive element and is configured to deliver said measurement of the orientation of the blades of the propeller. Said device for measuring the orientation of the blades 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 rotated with the rotary drive element and is arranged in the rotating frame. Insofar as saidmeasuring device and the motor control module are rotationally linked to the rotating drive element, and are therefore both arranged in the rotating frame, it is not necessary to transfer the measurement from the rotating frame to the fixed frame. Also, it is not necessary to provide the system with means for transmitting measurement data from a sensor arranged in the rotating frame to a motor control module which would be fixed relative to a portion of the aircraft frame. Preferably, the electric motor control module is configured to control said DC / AC inverter module in order to regulate said alternating voltage supplied by the latter to the stator of the electric motor. Said control module makes it possible to adjust the alternating voltage delivered by the DC / AC inverter module from the main direct voltage which it receives from the rectifier device. The control module advantageously makes it possible to adjust the frequencyand the amplitude of the alternating voltage delivered by the DC / AC inverter module. Advantageously, 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 aircraft frame, 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 control module of the electric motor. The signal transfer system makes it possible to transfer the setpoint signal(s) from the fixed reference frame to the rotating reference frame. Indeed, the signal transfer member makes it possible to transfer the setpoint signal from the control device, which is arranged in the fixed reference frame, to the control module of the motor which is rotationally linked to the rotating drive element, and which is therefore arranged in the rotating reference frame. Preferably, the system comprisesa reduction device comprising:- a sun gear rotatably linked to said turbine of the aircraft; - a crown to which said rotary drive element is rotatably linked; - a planet carrier fixed relative to a portion of the aircraft frame;- at least one satellite mounted pivotally relative to the satellite carrier and cooperating with said sun gear and said crown so that said rotary drive element is rotated when the sun gear is rotated. Said satellite is meshed with the sun gear as well as with the crown. The crown rotates at a reduced speed relative to the rotational speed of the sun gear, according to the reduction ratio of said reduction device. Said reduction device advantageously comprises an epicyclic gear train. The reduction device makes it possible to easily adapt the rotational speed of the rotary drive element. The invention further relates to an aircraft comprising at least one propeller comprisinga plurality of blades and a propeller blade pitch adjustment and deicing system as described above. The invention will be better understood upon reading the following description of embodiments of the invention given as non-limiting examples, with reference to the appended drawings, in which: [Fig. 1]Figure 1 illustrates a first embodiment of a system for adjusting the pitch and deicing the blades of a propeller of an aircraft according to the invention; [Fig. 2]Figure 2 illustrates a second embodiment of a system for adjusting the pitch and deicing the blades of a propeller of an aircraft according to the invention; [Fig. 3]Figure 3 illustrates a third embodiment of a system for adjusting the pitch and deicing the blades of a propeller of an aircraft according to the invention; and [Fig. 4]Figure 4 is a sectional view of a part of a turbomachine comprising a system according to the invention, in the area of ​​the propeller. The invention relates to a system for adjusting the pitch and deicing the blades of a propeller of an aircraft, said system being provided with a rotating transformer. The invention further relates to an aircraft comprising such a system. Figure 1 shows a first embodiment of a system 10 for adjusting the pitch and deicing the blades of a propeller of an aircraft, according to the invention. In this non-limiting example, the aircraft comprises a turbomachine 100, which may be a turbojet, a turbofan or a turboprop. A part of this turbomachine 100 is illustrated in figure 1. The turbomachine comprises a propeller 12 comprising a plurality of blades 14. Only one of said blades 14 is illustrated in figure 1. 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. The system 10 further comprises a rotary drive element 20 movable in rotation relative to a portion of the aircraft frame, around a main axis X. The rotary drive element 20 comprises a drive shaft. The rotary drive element 20 is configured to be driven in rotation by a low-pressure turbine of the turbomachine 100, via a reduction device 24. The reduction device 24 comprises an epicyclic gear train. More precisely, this reduction device 24 comprises a sun gear 26, a planet carrier 28, at least one satellite 30, only one being illustrated in FIG. 1, and a ring gear 32. The sun gear 26 is configured to be driven by the low pressure turbine of the turbomachine 100 around the main axis X.The planet carrier 28 is fixed relative to a portion of the aircraft frame. The satellite 30 is meshed with the sun gear 26 and the ring gear 32 and rotates relative to the planet carrier. The rotary drive element 20 is rotationally connected and secured to the ring gear 32. The ring gear 32 also rotates about the main axis X. The rotation of the sun gear 26 causes the rotation of the ring gear 32, and therefore of the rotary drive element 20, at a rotational speed lower than the rotational speed of the sun gear 26, according to a reduction ratio of the reduction device. The reduction device 24 has a reduction ratio of less than 1, preferably a reduction ratio of approximately 1 / 15.The propeller 12 of the aircraft is rotationally connected to said rotary drive element 20, so that it rotates at the same rotational speed as the latter, around the main axis X, as illustrated in FIG. 4 showing a sectional view of a portion of the turbomachine 100 comprising the system 10 according to the invention, in the area of ​​the propeller 12. Referring again to FIG. 1, it can be seen that the aircraft here comprises a continuous electrical power source 38 forming a DC bus, constituted by a continuous power supply network of the aircraft. Said electrical power source 38 is configured to deliver a direct voltage V. DCconstant. The system further comprises a rotating transformer 40 of the low radius transformer type. The rotating transformer 40 comprises a primary circuit 42 comprising at least one winding and a secondary circuit 44 comprising at least one winding. The primary circuit 42 is fixed relative to a portion of the aircraft frame and is therefore arranged in the fixed frame. It is secured to a fixed support, linked to the planet carrier 28 of the reduction device 24. The secondary circuit 44 is linked in rotation to the rotating drive element 20 and is arranged in the rotating frame. The system 10 also comprises an inverter device 46 electrically connected to the primary circuit 42 of the rotating transformer 40. The inverter device 46 is also connected to the electrical power source 38. In the embodiment of FIG. 1, the inverter device 46 comprises a fixed duty cycle inverter 48.The inverter device 46 further comprises a capacitor 50 connected between the input terminals of the fixed duty cycle inverter 48. The capacitor 50 presents the direct voltage V across its terminals. DC constant delivered by the electrical power source 38. The inverter device 46 is configured to deliver a primary alternating voltage Vp AC to the primary circuit 42 of the rotating transformer from the constant direct voltage VDC supplied by the electrical power source 38. The rotating transformer 40 is configured to transfer electrical energy from the electrical power source 38, and therefore from the fixed reference, to the electric motor 80 and said defrosting device 90, and therefore to the rotating reference. The rotating transformer delivers a secondary alternating voltage Vs AC . The secondary winding 44 has said secondary alternating voltage Vs ACat its terminals. The system 10 further comprises a rectifier device 52 connected to the secondary circuit 44 of the rotating transformer 40. The rectifier device 52 is rotationally connected to the rotating drive element 20 and is arranged in the rotating frame of reference. This rectifier device 52 comprises a rectifier member 54, formed by an AC / DC converter, and a filtering capacitor 56 connected between the output terminals of the rectifier member 54. The rectifier device 52 is configured to deliver a main DC voltage Vg DC from said secondary alternating voltage Vs AC . According to the invention, said rectifier device 52 is shared and delivers said main direct voltage Vg DCwhich allows the joint power supply of the electric motor 80 and the de-icing device 90. In the embodiment of Figure 1, the rectifier device 52, and more precisely the rectifier member 54, are active and can be controlled in order to adjust the voltage that they deliver. 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 further comprises a control device 91 for the de-icing device 90. This control device 91 is connected to the output of the rectifier device 52. It is powered by the main DC voltage Vg DCdelivered by the rectifier device 52. The control device 91 of the defrosting device comprises a control module 92 and a DC / DC converter 93 which are both connected to said rectifier device 52. The control module 92 is connected between the DC / DC converter 93 and the defrosting device 90. The DC / DC converter 93 is configured to deliver a direct defrosting voltage V dDC from said main direct voltage Vg DC . It is configured to adjust the defrost DC voltage V dDC which it provides for defrosting needs. The control module 92 receives said voltage and configured to distribute power to the defrosting device. The control module 92 comprises a plurality of switches and is configured to selectively drive the heating mats of the defrosting device 90 according to a selected sequence, from the direct voltage and therefore of said main DC voltage VgDC supplied by the rectifier device 52. The control module 92 makes it possible to select the blades 14 to be defrosted. The control module 92 is configured to control the defrosting device according to a defrosting setpoint C2. The defrosting device 90 and the control device 91 are rotationally connected to the rotary drive element 20 and are arranged in the rotating frame of reference. The system 10 further comprises a DC / AC inverter module 72 connected to the rectifier device 52. The DC / AC inverter module 72 is configured to supply an AC voltage Vm to the stator 82 of the electric motor 80 from the main DC voltage Vg DCsupplied by said rectifier device 52. The DC / AC inverter module 72 is also rotationally connected to the rotary drive element 20 and arranged in the rotating frame of reference. The assembly formed by the rectifier device 52 and the DC / AC inverter module 72 makes it possible to adjust the frequency and amplitude of the alternating voltage V m supplied to the electric motor 80. The electric motor 80 is supplied with electrical energy by the main direct voltage Vg DCdelivered by the rectifier device 52, via the DC / AC inverter module 72 which transforms it into an alternating voltage Vm. The main direct voltage delivered by the rectifier device 52 is used to jointly power the electric motor 80 and the de-icing device 90. 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 linked in rotation to the rotary drive element 20. It is configured to deliver a measurement a1 of the orientation of the blades of the propeller, considered along the longitudinal axis of said blades. The system further comprises a control module 74 of the electric motor 80. This control module 74 is configured to control the DC / AC inverter module 72 in order to regulate the alternating voltage powering the stator 82 of the electric motor, from a pitch setpoint C1 of the blades 14 of the propeller 12 of the aircraft and the measurement a1 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 linked in rotation to the rotary drive element 20 and is arranged in the rotating frame. The system 10 also comprises a control device 88 configured to generate said pitch setpoint C1 of the blades 14 of the propeller 12. This control device 88 is fixed relative to a portion of the frame of the aircraft and is therefore arranged in the fixed frame. The system 10 further comprises a signal transfer member 96 configured to transfer said pitch setpoint C1 of the blades from said control device 88 to the control module 74 of the electric motor 80.In other words, the signal transfer member 96 makes it possible to transfer the blade pitch setpoint signal C1 from the fixed reference frame into the rotating reference frame. The control device 88 is further configured to generate said defrost setpoint C2, intended for the control module 92 of the control device 91 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 defrost setpoint C2 from said control device 88 to the control module 74 of the electric motor 80. In other words, the signal transfer element 98 makes it possible to transfer the defrost setpoint signal C2 from the fixed reference frame into the rotating reference frame. The stator 82 of the electric motor 80 is connected in rotation to the rotary drive element 20 so that it is arranged in the rotating reference frame. Said stator 82 rotates around the main axis X.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 powered. The system 10 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. According to the invention, the system 10 further comprises a regulation unit 60 making it possible to maintain said main DC voltage delivered by said rectifier device 52 at a constant value.This regulation unit 60 comprises a control member 62 and a measuring member 64 configured to measure voltages and transmit them to the control member 62. In the first embodiment of FIG. 1, the regulation unit 60 is configured to control said rectifier device 52 so as to regulate the main DC voltage Vg. DC which it delivers to the defrosting device 90 and to the electric motor 80 as a function of a measurement m of said main direct voltage Vg DC, in order to maintain said main direct voltage Vg DC constant. More precisely, the measuring member 64 is configured to measure said main DC voltage Vg DC The control member 62 is configured to control the rectifier device 52 as a function of this measurement m of the main DC voltage supplied by the measuring member 64 in order to maintain said main DC voltage Vg. DCconstant. The measuring member 64 and the control member 62 and therefore more generally the regulation unit 60 are here linked in rotation to the rotary drive element 20. They are therefore arranged in the rotating reference frame. An advantage is that it is not necessary to transmit the measurement signals from the rotating reference frame to the fixed reference frame. The regulation unit makes it possible to control said main DC voltage Vg DCsupplied by the rectifier device 52 and to keep it constant, independently of the control of the electric motor 80 and the energy that it draws from the output of the rectifier device. The system makes it possible to independently regulate the voltage delivered by the rectifier device 52 and the supply voltage Vm of the electric motor, via two separate regulations. In a second embodiment illustrated in Figure 2, the system differs from that of Figure 1 by the configuration of the regulation unit 60'. The inverter device 46 here comprises a controlled inverter 48. In this second embodiment, the regulation unit 60' is configured to control said inverter device 46, and more precisely the controlled inverter 48, so as to regulate the primary alternating voltage VpAC that it delivers to the primary circuit 42 of the rotating transformer 40, always so as to maintain said main direct voltage Vg DCconstant. The regulation unit 60' controls the inverter device 46 as a function of a measurement m' of said main direct voltage Vg DC. More specifically, the measuring member 64' is configured to measure said main DC voltage VgDC. The control member 62' is configured to control the inverter device 46 as a function of this measurement m' of the main DC voltage supplied by the measuring member 64'. In this embodiment, the measuring member 64' is linked in rotation to the rotary drive element 20 and is arranged in the rotating frame. The control member 62' is fixed relative to a frame portion of the aircraft and is therefore arranged in the fixed frame. Consequently, the regulation unit 60' comprises a signal transfer member 66 configured to transfer the measurement signals from the measuring member 64' to the control member 62'. The signal transfer member 66 makes it possible to transfer the measurement signals from the rotating frame to the fixed frame. In this embodiment, the main DC voltage Vg DCis controlled by a constant value indirectly by acting on said primary alternating voltage Vp AC of the primary circuit 42 of the rotating transformer 40. In a third embodiment illustrated in Figure 3, the system is distinguished from those of Figures 1 and 2 by the configuration of the regulation unit 60''. The inverter device 46 here comprises a controlled inverter 48. In this third embodiment, the regulation unit 60'' is configured to control said inverter device 46 so as to regulate the primary alternating voltage Vp AC which it delivers to the primary circuit 42 of the rotating transformer 40, always so as to maintain said main direct voltage Vg DC constant. The regulation unit 60'' controls the inverter device 46 according to a measurement m'' of this same primary alternating voltage VpAC. More precisely, the measuring device 64'' is configured to measure said primary alternating voltage VpAC. The control member 62'' is configured to control the inverter device 46 as a function of this measurement m'' of the primary alternating voltage supplied by the measuring member 64'', to maintain the main direct voltage constant. In this third embodiment, the measuring member 64'' and the control member 62'', and more generally the regulation unit 60'', are fixed relative to a portion of the aircraft frame and are therefore arranged in the fixed reference frame. The control member 62'' is fixed relative to a portion of the aircraft frame and is therefore arranged in the fixed reference frame. An advantage is that it is not necessary to transmit the measurement signals from the rotating reference frame to the fixed reference frame. Furthermore, to the extent that the control member 62'' is arranged in the fixed reference frame, said control is all the more reliable.In this third embodiment, the main direct voltage VgDC is controlled to a constant value indirectly by acting on said primary alternating voltage Vp. AC .

Claims

Claims 1. System (10) for adjusting the pitch and de-icing the blades (14) of a propeller (12) of an aircraft comprising an electrical power source (38) delivering a constant direct voltage (VDC), the system comprising: - a rotary drive element (20) configured to be driven in rotation by a turbine of the aircraft; - an electric motor (80) comprising a stator (82) linked in rotation to said rotary drive element and a rotor (84) pivoting relative to the stator and used to adjust the pitch of the blades of the propeller of the aircraft; - a de-icing device (90) of said blades of the propeller linked in rotation to said rotary drive element; - an inverter device (46) configured to be connected to the electrical power source and to deliver a primary alternating voltage (Vp AC) from the constant direct voltage delivered by said electrical power source; - a rotating transformer (40) comprising a primary circuit (42) fixed relative to a portion of the aircraft frame and connected to the inverter device (46) so that it receives the primary alternating voltage (Vp AC ), and a secondary circuit (44) rotationally connected to said rotary drive element and delivering a secondary alternating voltage (Vs AC ); - a rectifier device (52) connected to the secondary circuit and configured to deliver a main DC voltage (Vg DC ) from said secondary alternating voltage supplied by said secondary circuit, for supplying electrical energy to the electric motor and the defrosting device; -a DC / AC inverter module (72) rotatably connected to said rotary drive element and configured to supply an alternating voltage (V m) to said stator (82) of the electric motor from the main direct voltage (Vg DC ) supplied by the rectifier device; - a control device (91) of the defrosting device (90) powered by said main direct voltage (VgDC) and linked in rotation to the rotary drive element; and - a regulation unit (60,60',60'') configured to maintain said main direct voltage at a constant value.

2. System according to claim 1, wherein the regulation unit is configured to regulate said main direct voltage (VgDC) delivered by the rectifier device (52) or said primary alternating voltage (Vp AC) delivered by the inverter device (46) from a measurement (m,m',m'') of one or the other of the latter, so as to maintain said main DC voltage at a constant value.

3. System according to claim 2, wherein said regulation unit (60) is configured to control said rectifier device (52) so as to regulate the main DC voltage (Vg DC ) delivered by the rectifier device as a function of a measurement (m) of said main DC voltage, so as to maintain said main DC voltage at a constant value.

4. System according to claim 3, wherein said regulation unit (60) comprises a control member (62) configured to control said rectifier device (52) and a measuring member (64) communicating with the control member and configured to measure said main DC voltage (Vg DC) delivered by the rectifier device, the control member and the measuring member being rotationally linked to said rotary drive element (20).

5. System according to claim 2, in which the regulation unit (60') is configured to control said inverter device (46) so as to regulate the primary alternating voltage (Vp AC ) delivered by the inverter device from a measurement (m') of the main DC voltage (VgDC) delivered by the rectifier device (52), so as to maintain said main DC voltage at a constant value.

6. System according to claim 5, wherein said regulation unit (60') comprises a control member (62') configured to control said inverter device (46) and a measuring member (64') communicating with the control member and configured to measure said main DC voltage (Vg DC ) delivered by the rectifier device (52), the control member being fixed relative to a frame portion of the aircraft while the measuring member is rotationally connected to said rotary drive element (20).

7. System according to claim 2, wherein the regulation unit (60'') is configured to control said inverter device (46) so as to regulate the primary alternating voltage (Vp AC ) delivered by the inverter device from a measurement (m'') of said primary alternating voltage delivered by the inverter device, so as to maintain said main direct voltage (Vg DC ) to a value c onstante.

8. System according to claim 7, wherein said regulation unit (60'') comprises a control member (62'') configured to control said inverter device (46) and a measuring member (64'') communicating with the control member and configured to measure said primary alternating voltage (Vp AC) delivered by the inverter device, the control member and the measuring member being fixed relative to a portion of the aircraft frame.

9. System according to any one of claims 1 to 8, wherein the control device (91) of the deicing device comprises a DC / DC converter (93) configured to deliver a direct deicing voltage (V dDC ) from said main direct voltage (Vg DC) and a control module (92) receiving said deicing DC voltage and configured to distribute the power to the deicing device.

10. System according to any one of claims 1 to 9, further comprising a control module (74) of the electric motor (80) configured to regulate the voltage (Vm) at the stator (82) of the electric motor, from a pitch setpoint (C1) of the blades (14) of the propeller (12) of the aircraft and from a measurement (a1) of the orientation of the blades of the propeller of the aircraft, said motor control module being rotationally linked to said rotary drive element (20).

11. System according to claim 10, wherein the control module (74) of the electric motor (80) is configured to control said DC / AC inverter module (72) in order to regulate said alternating voltage (V m) supplied by the latter to the stator (82) of the electric motor.

12. System according to claim 10 or 11, further comprising a control device (88) configured to generate said pitch setpoint (C1) 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 (C1) of the blades of the propeller of the aircraft from said control device to the control module (74) of the electric motor (80). 13.System according to any one of claims 1 to 12, comprising a reduction device (24) comprising: - a sun gear (26) rotatably connected to said turbine of the aircraft; - a ring gear (32) to which said rotary drive element (20) is rotatably connected; - a planet carrier (28) fixed relative to a portion of the aircraft frame; - at least one satellite (30) pivotally mounted relative to the planet carrier and cooperating with said sun gear and said ring gear so that said rotary drive element is rotated when the sun gear is rotated.

14. 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 13.

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