Propeller pitch adjustment and de-icing system for an aircraft propeller, comprising a rotating transformer

Abstract

Pitch adjustment and de-icing system for the blades of an aircraft propeller comprising a rotating transformer. Pitch adjustment and de-icing system (10) for the blades (14) of an aircraft propeller (12) comprising a rotating drive element (20); an electric motor (80); a de-icing device (90) for said blades; an inverter device (46) delivering a primary alternating voltage (VpAC); a rotating transformer (40) having a primary circuit (42) receiving the primary alternating voltage (VpAC) and a secondary circuit (44) delivering a secondary alternating voltage (VsAC); a rectifier device (52) delivering a primary direct current voltage (VgDC) from said secondary alternating voltage; a DC / AC inverter module (72) configured to supply an alternating voltage (Vm) to the stator (82) of the electric motor from the primary direct current voltage (VgDC);a control device (91) for the defrosting device (90) powered by said main DC voltage (VgDC); and a regulation unit (60,60',60'') configured to maintain said main DC voltage at a constant value. Figure for the abstract: Fig. 1.;

Description

Title of the invention: Propeller pitch adjustment and de-icing system for an aircraft propeller comprising a rotating transformer technical field

[0001] The present invention relates to a system for simultaneously adjusting the pitch of an aircraft propeller blades and de-icing said blades, for example by means of heating mats associated with the blades. The aircraft may comprise a turbofan or turbojet engine, 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. Previous technique

[0002] 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.

[0003] Most propeller blades equipping turboprops or turbofans are fitted with a de-icing system using heated mats that prevent ice formation. Their power supply is provided by a brush commutator, which presents numerous problems: - significant wear and tear requiring regular maintenance; - a heavy and bulky device.

[0004] Current solutions propose transferring electrical energy from the fixed frame to the rotating frame by means of a rotating transformer, with or without brushes. However, this solution presents a major drawback due to its complexity and integration constraints, such as: - a large diameter of the rotating transformer if it is located downstream of the step actuation system and if it is attached to the fixed structure of the turbine machine; - difficulties accessing the fixed support if it is located upstream of the conventional hydraulic step actuation system; - difficulties in routing the harnesses for supplying the primary circuit of the rotating transformer in the fixed reference frame.

[0005] Moreover, a conventional hydraulic pitch control system has a hydraulic transfer from the fixed part to the rotating part which does not offer easy access to the fixed part on the cone side of the turbomachine.

[0006] Furthermore, the three-phase or single-phase rotating transformer transfers the power The electrical power required corresponds to the need, which determines its significant mass. A DC / AC power converter of equivalent power must therefore be provided.

[0007] It may therefore be desirable to design a system that overcomes all or part of the aforementioned constraints.

[0008] Some systems provide for jointly powering the electric motor for blade pitch adjustment and the blade de-icing device by means of a shared generator. One drawback is that driving such a generator at low speeds is complex and requires sizing the generator accordingly, significantly increasing its size.

[0009] Other systems provide for jointly powering the electric blade pitching motor and the de-icing device via a rotating transformer allowing the transfer of electrical energy from an aircraft power supply source, located in a fixed reference point on the aircraft, to said electric motor and said de-icing device.

[0010] 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 a power supply and a secondary circuit connected to the electric motor and 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 transformer's primary circuit, and therefore indirectly the secondary alternating voltage, based on measurements of the propeller blade orientation.

[0011] One drawback of the solution described in this document is that with each variation in the rotational speed setpoint of the electric motor, the electric motor draws a different amount of energy from the transformer's secondary circuit, resulting in different current draws. This causes the secondary AC voltage supplied by the transformer to vary. In other words, this secondary AC voltage is subject to variation and is dependent on the operation of the electric motor. Consequently, the secondary AC voltage may prove insufficient to properly power the defrosting device. In particular, the power drawn by the defrosting device, and especially by its heating mats, may be affected, which necessitates adjusting the control of the defrosting device and the heating mats according to the available energy resources.

[0012] If, on the other hand, the control of the defrosting system is adapted to its needs, the impact will be localized at the level of the step control device. Indeed, the regulation of the voltage delivered by the rotating transformer to respect the power required for The defrosting system involves a wide voltage range. The electric motor of the step control device must be sized to withstand this wide voltage range, which will result in a significant mass. Description of the invention

[0013] One object of the present invention is to propose a pitch adjustment and de-icing system for the blades of an aircraft propeller that remedies the aforementioned drawbacks.

[0014] To this end, the invention relates to a pitch adjustment and de-icing system for the blades of an aircraft propeller, comprising a power supply delivering a constant direct current voltage, the system comprising: - a rotary drive element configured to be driven in rotation by a turbine of the aircraft; - an electric motor comprising a stator linked in rotation to said rotating drive element and a rotor pivoting relative to the stator and used to adjust the pitch of the aircraft propeller blades; - a de-icing device for said propeller blades linked in rotation to said rotating drive element; - an inverter device configured to be connected to the power supply and to deliver a primary alternating voltage from the constant direct current voltage delivered by said power supply; - 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 linked in rotation to said rotating drive element and delivering a secondary alternating voltage; - a rectifier device connected to the secondary circuit and configured to deliver a main DC voltage from said secondary AC voltage supplied by said secondary circuit, for the electrical power supply of the electric motor and the defrosting device; - a DC / AC inverter module linked in rotation to said rotating drive element and configured to provide an alternating voltage to said electric motor stator from the main DC voltage supplied by the rectifier device; - a control device for the defrosting device, powered by said main DC voltage and rotationally linked to the rotary drive element; and - a regulating unit configured to maintain said main DC voltage at a constant value.

[0015] By way of non-limitation, the aircraft advantageously comprises a turbomachine including said system according to the invention. For example, said turbomachine may be A turbofan or turbojet engine, in which case the propeller is called a fan and the blades are called blades, or a turboprop. In other words, the term "propeller" covers both the propeller of a turboprop engine and the fan of a turbojet or turbofan. The term "blades" covers both the propeller blades of a turboprop engine and the fan blades of a turbojet or turbofan. Preferably, the aircraft propeller is rotationally linked to the rotating drive element, so that it rotates at the same speed. The propeller is advantageously supported by the rotating drive element.

[0016] The power supply is advantageously a DC bus of the aircraft. Without limitation, said power supply may be a DC power network of the aircraft. This power supply is advantageously fixed relative to a portion of the aircraft frame and is therefore located in the fixed frame.

[0017] The rotary drive element is configured to rotate about a main axis. The rotary drive element may include a drive shaft. The rotary drive element is advantageously driven in rotation by the aircraft turbine, via a reduction gear. It also rotates at a lower rotational speed than the rotational speed of this turbine. The rotary drive element is advantageously driven in rotation by a low-pressure turbine of an aircraft turbomachine. The rotary drive element defines a rotating frame of reference, as opposed to a fixed frame of reference corresponding to the frame of a portion of the aircraft structure.

[0018] By rotationally linked, it is understood that the transformer's secondary circuit, the defrosting device, and the electric motor's stator describe the same rotational movement as said rotary drive element. They rotate at the same speed as this rotary drive element. Preferably, the transformer's secondary circuit, the defrosting device, and / or the electric motor's stator are supported by said rotary drive element, or even more preferably, are integral with said rotary drive element. The rotary drive element advantageously forms a rotating support for the secondary circuit, the defrosting device, and the electric motor's stator.

[0019] The inverter device provides 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 power supply 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 located in a fixed position. Without limitation, the inverter device may be passive or controlled.

[0020] The inverter device advantageously comprises an inverter and a capacitor connected between the input terminals of said inverter. Said capacitor advantageously presents across its terminals the constant DC voltage supplied by the power supply.

[0021] The secondary circuit of the rotating transformer presents said secondary alternating voltage at its terminals.

[0022] The de-icing device advantageously comprises a plurality of heating mats associated with the aircraft propeller blades and enabling the removal of ice. The heating mats can advantageously be selectively controlled, for example by means of switches. The de-icing device is located in the rotating reference frame.

[0023] The defrosting device is electrically powered via the defrosting device control device, through the rotating transformer and the rectifier device.

[0024] Said control device of the defrosting device is rotationally linked, preferably supported, by the rotating drive element. It is advantageously arranged in the rotating frame.

[0025] The control device is advantageously connected to the rectifier device. It is advantageously connected between the rectifier device and the defrosting device.

[0026] The defrosting device control unit allows the defrosting unit to be controlled in order to control the defrosting of the propeller blades. The control unit regulates the power supplied to the defrosting unit, and in particular to the heating mats. It is advantageously configured to selectively power the heating mats of the defrosting unit. In other words, it allows the selection of the blades to be defrosted.

[0027] The voltage required to supply the heating mats of the defrosting device is advantageously adjusted by controlling the defrosting device control unit.

[0028] Preferably, the 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 allows control of the frequency and amplitude of the alternating voltage supplied to the electric motor. Preferably, the DC / AC inverter module includes a DC / AC converter.

[0029] Preferably, the electric motor includes said DC / AC inverter module.

[0030] The electric motor allows the orientation of the propeller blades to be adjusted around their longitudinal axes, also known as blade pitch. Without limitation, the electric motor may be a synchronous motor or a motor Asynchronous. Preferably, the stator and rotor of the electric motor rotate about the main axis around which the rotating drive element rotates. Preferably, the electric motor is configured to drive an actuation system designed to adjust the pitch of the aircraft propeller blades. The actuation system may be electro-hydraulic (EHA), comprising, for example, a pump, or electromechanical (EMA), comprising, for example, a screw and nut. These actuation systems allow for adjusting the pitch of the aircraft propeller blades.

[0031] The rotating transformer is advantageously a low-radius transformer. It is configured to transfer electrical energy from the power supply to the electric motor and the defrosting device. The primary circuit of the rotating transformer advantageously comprises at least one winding. The primary circuit is located in the fixed frame. The secondary circuit of the rotating transformer advantageously comprises at least one winding. The secondary circuit of the rotating transformer is driven in rotation by the rotating drive element and is advantageously supported by it. The secondary circuit is located in the rotating frame. The secondary circuit of the rotating transformer rotates relative to the primary circuit. The primary circuit is advantageously supported by a fixed support element.

[0032] The rectifier device connected to the secondary circuit of the transformer is advantageously rotationally linked to the rotating drive element. It is therefore advantageously positioned in the rotating frame of reference.

[0033] Preferably, the rectifier device comprises a rectifier element and a filter capacitor connected between the output terminals of the rectifier element. The main DC voltage is then the voltage across the filter capacitor.

[0034] According to the invention, the rotating transformer is shared for the power supply of said electric motor and said defrosting device. Similarly, said rectifier device is also shared for the power 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.

[0035] The system control unit according to the invention allows the main DC voltage supplying the electric motor and the defrosting device to be regulated so as to maintain it at a constant value. Without departing from the scope of the invention, this regulation can be achieved either directly by directly regulating said main DC voltage, or indirectly by regulating, for example, the primary AC voltage of the transformer's primary circuit.

[0036] The system control unit according to the invention allows the main DC voltage to be regulated to a constant value for the power supply of the electric motor and the defrosting device. The system control unit according to the invention allows said main DC voltage to be regulated to 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 the rectifier device. Thanks to the invention, said main DC voltage is therefore maintained constant and steady. 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.

[0037] It is therefore not necessary to size the electric motor for adjusting the blade pitch to withstand a wide voltage range. Consequently, the weight and size of the electric motor can be reduced.

[0038] In other words, according to the invention, the regulation of the main DC voltage supplied to the electric motor and the defrosting device is independent of the control of the electric motor. The control of the electric motor can be achieved by means of a control unit independent of said regulation unit.

[0039] Preferably, the control unit is configured to regulate the main DC voltage delivered by the rectifier device or the primary AC voltage delivered by the inverter device based on a measurement of either of these, so as to maintain the main DC voltage at a constant value. An advantage is that this regulation is performed based on 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 achieved by taking into account the voltage variations upstream or downstream of the rotating transformer, by measuring these voltages. The control unit allows the main DC voltage to be controlled to a constant value.

[0040] It is understood here again that the regulating unit is configured to maintain said main DC voltage at a constant value either directly by directly regulating the latter, or indirectly by regulating the primary AC voltage of the transformer's primary circuit.

[0041] According to a first advantageous embodiment, said control unit is configured to control said rectifier device so as to regulate the main DC voltage delivered by the rectifier device as a function of a measurement of said main DC voltage, so as to maintain said main DC voltage at a constant value. In this embodiment, the control unit allows direct control of the main DC voltage, which powers the electric motor and the defrosting device, based on a measurement of this voltage. One advantage is the ability to regulate the main DC voltage delivered by the rectifier device more precisely to a constant value. Another advantage is that it allows the control unit to be positioned entirely within the rotating frame and to be rotationally linked to the rotating drive element.

[0042] The inverter device advantageously comprises a fixed duty cycle inverter.

[0043] Advantageously, said control unit comprises a control element configured to control said rectifier device and a measuring element communicating with the control element and configured to measure said main DC voltage delivered by the rectifier device, the control element and the measuring element being rotationally linked to said rotary drive element.

[0044] The measuring element is configured to transmit said measurement of the main DC voltage to the control element. The control element is configured to control the rectifier device according to said measurement of the main DC voltage.

[0045] The control element and the measuring element are rotationally linked to the rectifier device, the secondary circuit of the rotating transformer, and the stator of the electric motor. One advantage is that it eliminates the need for a signal transfer means between the fixed reference frame and the rotating reference frame for transmitting measurement data between the measuring element and the control element, since both are located within said rotating reference frame and can communicate within that frame.

[0046] According to a second advantageous embodiment, the control 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.

[0047] In this embodiment, the main DC voltage delivered by the rectifier device is indirectly controlled by regulating the primary AC voltage delivered by the inverter device. However, the voltage regulation is particularly precise since it is based on a measurement of said main DC voltage.

[0048] One advantage is to allow a control element of the regulation unit to be placed in the fixed reference frame.

[0049] In this embodiment, the inverter device is controlled. Notwithstanding, the rectifier device is advantageously passive.

[0050] Preferably, said control unit comprises a configured control element to control said inverter device and a measuring element communicating with the control element and configured to measure said main DC voltage delivered by the rectifier device, the control element being fixed relative to a portion of the aircraft frame while the measuring element is rotationally linked to said rotating drive element.

[0051] It is understood that the control element is located in a fixed frame of reference, while the measuring element is located in a rotating frame of reference. One advantage of locating the control element in the fixed frame of reference is to improve its performance and avoid control alterations that can occur with a control element located in the rotating frame of reference. Furthermore, this configuration eliminates the need for an additional transmission module to transmit information from engine control units located in a fixed part of the frame to the control element. The measuring element is rotationally linked to the rectifier device, the transformer's secondary circuit, and the electric motor's stator.

[0052] The measuring element is configured to transmit the main DC voltage measurement to the control element. The control unit advantageously includes a signal transfer element configured to transfer the measurement signals from the measuring element to the control element. It is understood that the signal transfer element allows the measurement signals to be transferred from the rotating reference frame to the fixed reference frame. The control element is configured to control the inverter device based on the main DC voltage measurement.

[0053] According to a third advantageous embodiment, the control unit is configured to control said inverter device so as to regulate the primary AC voltage delivered by the inverter device based on a measurement of said primary AC voltage delivered by the inverter device, so as to maintain said primary DC voltage at a constant value

[0054] In this third embodiment, the main DC voltage delivered by the rectifier device is indirectly controlled by regulating the primary AC voltage delivered by the inverter device. Indeed, the main DC voltage is a representation of said primary AC voltage. This embodiment allows the entire control unit to be fixed relative to the aircraft frame and thus positioned in the fixed frame.

[0055] In this embodiment, the rectifier device is passive.

[0056] Advantageously, said control unit comprises a control element configured to control said inverter device and a measuring element communicating with the control element and configured to measure said primary alternating voltage delivered by the inverter device, the control element and the measuring element being fixed with respect to a portion of the aircraft frame.

[0057] The control element and the measuring element are located in the fixed reference frame, thus eliminating the need for a signal transfer element to transfer the measurement signals from the rotating reference frame to the fixed reference frame. Furthermore, one advantage of placing the control element in the fixed reference frame is to improve its performance and avoid control alterations that can occur with a control element located in the rotating reference frame. In addition, this configuration eliminates the need for an additional transmission module to transmit information from engine control units located in the fixed part of the frame to the control element. Moreover, the placement of the measuring element in the fixed reference frame also improves the accuracy of the measurements it performs.

[0058] Preferably, the defrosting device control device includes a DC / DC converter configured to deliver a defrosting DC voltage from said main DC voltage and a control module receiving said defrosting DC voltage and configured to distribute power to the defrosting device.

[0059] The control module and the DC / DC converter are rotationally linked, preferably supported, by the rotating drive element. They are advantageously arranged in the rotating frame.

[0060] The control module of the control device is advantageously configured to control the sequential power supply to the propeller blades. The control module is advantageously configured to selectively control and power the heating mats of the defrosting device, advantageously according to a chosen sequence. In other words, it allows selection of 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 includes at least one switch for selecting the heating mats to be powered.

[0061] The voltage required to supply the heating mats of the defrosting device is advantageously adjusted by controlling the DC / DC converter of the defrosting device control unit.

[0062] Preferably, but not limited to, the DC / DC converter and the control module of the defrosting device control unit are both connected to the rectifier device.

[0063] Preferably, the system includes a control device configured to generate a de-icing command for the de-icing device's control unit, preferably for the control module of said control unit. The control device is preferably fixed relative to a portion of the aircraft frame and is therefore located in the fixed reference frame. The system further includes at least one signal transfer element configured to transfer the defrosting command from the control device to the defrosting device control device. The signal transfer element transmits the defrosting command from the fixed reference point to the rotating reference point in which the defrosting device control device is located.

[0064] Preferably, the system further comprises an electric motor control module configured to regulate the voltage to the electric motor stator, based on a pitch setpoint of the aircraft propeller blades and a measurement of the orientation of the aircraft propeller blades, said motor control module being rotationally linked to said rotating drive element.

[0065] The motor control module is located in the rotating frame. Therefore, it is not necessary to provide an additional module to transmit control signals between the control module and the electric motor. The control module advantageously allows adjustment of the frequency and amplitude of the alternating voltage supplied to the electric motor. The electric motor control module allows adjustment of the rotational speed and direction of rotation of the electric motor's rotor.

[0066] Preferably, the system includes a device for measuring the orientation of the aircraft propeller blades which is rotationally linked to the rotating drive element and is configured to deliver said measurement of the orientation of the propeller blades.

[0067] Said blade orientation measurement device advantageously comprises a plurality of sensors, each associated with one of the propeller blades. It is understood that said measurement device is driven in rotation with the rotating drive element and is disposed in the rotating frame of reference.

[0068] Since the measuring device and the motor control module are rotationally linked to the rotating drive element, and are therefore both located in the rotating frame, it is not necessary to transfer the measurement from the rotating frame to the fixed frame. Therefore, it is not necessary to equip the system with means for transmitting measurement data from a sensor located in the rotating frame to a motor control module that is fixed relative to a portion of the aircraft frame.

[0069] Preferably, the electric motor control module is configured to control the DC / AC inverter module in order to regulate the alternating voltage supplied by the latter to the electric motor stator. The control module allows adjustment of the alternating voltage delivered by the DC / AC inverter module based on the main DC voltage it receives from the rectifier device. Advantageously, the control module allows adjustment of the frequency and amplitude of the alternating voltage delivered by the DC / AC inverter module.

[0070] Advantageously, the system includes a control device configured for The system generates the propeller pitch command for the aircraft, which is fixed relative to a portion of the aircraft frame. The system further comprises at least one signal transfer device configured to transfer the propeller pitch command from the control device to the electric motor control module. The signal transfer system enables the transfer of the command signal(s) from the fixed reference point to the rotating reference point.

[0071] Indeed, the signal transfer unit allows the setpoint signal to be transferred from the control device, which is located in the fixed frame, to the motor control module which is rotationally linked to the rotating drive element, and which is therefore located in the rotating frame.

[0072] Preferably, the system comprises a reducing device including: - a planetary gear linked in rotation to said aircraft turbine; - a ring to which the said rotating drive element is rotationally linked; - a satellite carrier fixed relative to a portion of the aircraft frame; - at least one satellite mounted pivoting relative to the satellite carrier and cooperating with said planetary and said ring so that said rotating drive element is driven in rotation when the planetary is driven in rotation.

[0073] Said satellite is meshed with the planetary gear and with the ring gear. The ring gear rotates at a reduced speed relative to the rotational speed of the planetary gear, according to the reduction ratio of said reduction device. Said reduction device advantageously comprises an epicyclic gear train. The reduction device allows for easy adjustment of the rotational speed of the rotating drive element.

[0074] The invention also relates to an aircraft comprising at least one propeller comprising a plurality of blades and a pitch adjustment and de-icing system for the propeller blades as described above. Brief description of the drawings

[0075] The invention will be better understood upon reading the following description of embodiments of the invention given by way of non-limiting examples, with reference to the accompanying drawings, in which:

[0076] [Fig.1] [Fig.1] illustrates a first embodiment of a pitch adjustment and de-icing system for the blades of an aircraft propeller according to the invention;

[0077] [Fig.2] [Fig.2] illustrates a second embodiment of a pitch adjustment and de-icing system for the blades of an aircraft propeller according to the invention;

[0078] [Fig. 3] [Fig. 3] illustrates a third embodiment of a propeller pitch adjustment and de-icing system for an aircraft propeller according to the invention; and

[0079] [Fig.4] [Fig.4] a cross-sectional view of part of a turbomachine comprising a system according to the invention, in the propeller area. Description of the implementation methods

[0080] The invention relates to a system for adjusting the pitch and de-icing the blades of an aircraft propeller, said system being equipped with a rotating transformer. The invention further relates to an aircraft comprising such a system.

[0081] Fig. 1 shows a first embodiment of a system 10 for pitch adjustment and de-icing of the blades of an aircraft propeller, according to the invention.

[0082] In this non-limiting example, the aircraft comprises a turbomachine 100, which may be a turbojet, a turbofan, or a turboprop. A portion of this turbomachine 100 is illustrated in [Fig. 1]. The turbomachine comprises a propeller 12 having a plurality of blades 14. Only one of said blades 14 is illustrated in [Fig. 1].

[0083] Said turbomachine 100 further comprises said system 10 for pitch adjustment and de-icing of the aircraft propeller blades, according to the invention. The system 10 comprises an electric motor 80 for adjusting the pitch of the propeller blades 14 of the propeller 12 and a de-icing device 90 for the blades, which will be described subsequently.

[0084] The system 10 further comprises a rotary drive element 20 that is movable in rotation relative to a portion of the aircraft frame, about a principal 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.

[0085] The reduction gear 24 includes an epicyclic gear train. More specifically, this reduction gear 24 comprises a planet gear 26, a planet carrier 28, at least one planet gear 30, only one of which is illustrated in [Fig. 1], and a ring gear 32. The planet 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 planet gear 30 is meshed with the planet gear 26 and the ring gear 32 and rotates relative to the planet carrier. The rotary drive element 20 is rotationally linked and fixed to the ring 32. The ring 32 also rotates around the main axis X. The rotation of the planetary gear 26 causes the rotation of the ring 32, and therefore of the rotary drive element 20, at a rotational speed lower than the rotational speed of the planetary gear 26, according to a reduction ratio of the reducing device.The reducing device 24 has a reduction ratio of less than 1, preferably a reduction ratio of about 1 / 15.

[0086] The aircraft propeller 12 is rotationally linked to said rotating 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 cross-sectional view of a portion of the turbomachine 100 comprising the system 10 according to the invention, in the propeller area. 12.

[0087] Referring again to [Fig. 1], it can be seen that the aircraft here includes a DC power supply 38 forming a DC bus, constituted by a DC power supply network for the aircraft. Said power supply 38 is configured to deliver a constant DC voltage VDC.

[0088] The system further comprises a rotating transformer 40 of the low-radius transformer type. The rotating transformer 40 comprises a primary circuit 42 including at least one winding and a secondary circuit 44 including at least one winding. The primary circuit 42 is fixed relative to a portion of the aircraft frame and is therefore located in the fixed frame. It is integral with a fixed support, which is linked to the planet carrier 28 of the reduction device 24. The secondary circuit 44 is rotationally linked to the rotary drive element 20 and is located in the rotating frame.

[0089] The system 10 also includes 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 power supply 38.

[0090] 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 across its terminals the constant DC voltage VDc supplied by the power supply 38.

[0091] The inverter device 46 is configured to deliver a primary alternating voltage VpAc to the primary circuit 42 of the rotating transformer from the constant direct current voltage VDC supplied by the power supply source 38.

[0092] The rotating transformer 40 is configured to transfer electrical energy from the power supply 38, and therefore from the fixed reference frame, to the electric motor 80 and the defrosting device 90, and thus to the rotating reference frame. The rotating transformer delivers a secondary alternating voltage VsAC. The secondary winding 44 presents said secondary alternating voltage VsAc across its terminals.

[0093] The system 10 further includes a rectifier device 52 connected to the secondary circuit 44 of the rotating transformer 40. The rectifier device 52 is rotationally linked to the rotating drive element 20 and is disposed in the rotating frame. This rectifier device 52 comprises a rectifier element 54, formed by an AC / DC converter, and a filter capacitor 56 connected between the output terminals of the rectifier element 54.

[0094] The rectifier device 52 is configured to deliver a main DC voltage VgDc from said secondary AC voltage VsAC. According to the invention, said rectifier device 52 is shared and delivers said main DC voltage VgDc which allows the joint power supply of the electric motor 80 and the defrosting device 90.

[0095] In the embodiment of [Fig. 1], the rectifier device 52, and more specifically the rectifier member 54, are active and can be controlled to adjust the voltage they deliver.

[0096] The de-icing device 90 comprises a plurality of heating mats, each associated with one of the blades 14 of the aircraft propeller 12. 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 VgDC supplied by the rectifier device 52.

[0097] The control device 91 of the defrosting device comprises a control module 92 and a DC / DC converter 93, both of which are 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 DC defrosting voltage VdDc from said main DC voltage VgDc. The DC converter 93 is configured to adjust the DC defrosting voltage VdDc it supplies to the defrosting requirements. The control module 92 receives said DC defrosting voltage VdDc and is configured to distribute power to the defrosting device.

[0098] The control module 92 comprises a plurality of switches and is configured to selectively control the heating mats of the defrosting device 90 according to a chosen sequence, based on the defrosting DC voltage VdDC and therefore on the main DC voltage VgDC supplied by the rectifier device 52. The control module 92 allows the selection of the blades 14 to be defrosted. The control module 92 is configured to control the defrosting device according to a defrosting setpoint C2.

[0099] The defrosting device 90 and the control device 91 are rotationally linked to the rotating drive element 20 and are arranged in the rotating reference frame.

[0100] 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 alternating voltage Vm to the stator 82 of the electric motor 80 from the main direct current voltage VgDC supplied by said rectifier device 52. The DC / AC inverter module 72 is also rotationally linked to the rotary drive element 20 and disposed in the rotating frame. The assembly formed by the rectifier device 52 and the DC / AC inverter module 72 allows the frequency and amplitude of the alternating voltage Vm supplied to the electric motor 80 to be adjusted.

[0101] The electric motor 80 is supplied with electrical energy by the main DC voltage VgDc delivered 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 defrosting device 90.

[0102] The system includes a measuring device 86 for the orientation of the propeller blades 14 of the aircraft propeller 12. This measuring device 86 comprises a plurality of sensors associated with the propeller blades 14. The measuring device 86 is rotationally linked to the rotary drive element 20. It is configured to deliver a measurement α of the orientation of the propeller blades, considered along the longitudinal axis of said blades.

[0103] The system further includes a control module 74 for 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 Vm supplying the stator 82 of the electric motor, based on a setpoint Ci for the pitch of the blades 14 of the aircraft propeller 12 and the measurement ai of the orientation of the aircraft propeller blades provided by the measuring device 86. Said control module 74 for the electric motor 80 is rotationally linked to the rotary drive element 20 and is disposed in the rotating frame.

[0104] The system 10 also includes a control device 88 configured to generate the propeller pitch setpoint Ci for the propeller blades 14 of the propeller 12. This control device 88 is fixed relative to a portion of the aircraft frame and is therefore located in the fixed reference frame. The system 10 further includes a signal transfer element 96 configured to transfer the propeller pitch setpoint Ci from the control device 88 to the control module 74 of the electric motor 80. In other words, the signal transfer element 96 enables the transfer of the propeller pitch setpoint Ci signal from the fixed reference frame to the rotating reference frame.

[0105] The control device 88 is further configured to generate said defrosting setpoint C2 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 includes a signal transfer element 98 configured to transfer said defrosting 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 allows the defrosting setpoint signal C2 to be transferred from the fixed reference frame to the rotating reference frame.

[0106] The stator 82 of the electric motor 80 is rotationally linked to the rotating drive element 20 such that it is positioned in the rotating frame. Said stator 82 rotates about the main axis X. 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 energized.

[0107] The system 10 further comprises an actuation system 16 configured for Adjusting the orientation of the propeller blades 12. The actuation system 16 can be electro-hydraulic or electromechanical. This 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 cylinder (electro-hydraulic system) or a nut (electro-mechanical system). This translational movement is then converted into a rotational movement of the propeller blades 14 via a connecting rod and crank mechanism 18.

[0108] According to the invention, the system 10 further comprises a control unit 60 for maintaining the main DC voltage delivered by the rectifier device 52 at a constant value. This control unit 60 comprises a control element 62 and a measuring element 64 configured to measure voltages and transmit them to the control element 62.

[0109] In the first embodiment of [Fig. 1], the control unit 60 is configured to control said rectifier device 52 so as to regulate the main DC voltage VgDc that it delivers to the defrosting device 90 and the electric motor 80 according to a measurement m of said main DC voltage VgDc, in order to maintain said main DC voltage VgDc constant. More specifically, the measuring element 64 is configured to measure said main DC voltage VgDc. The control element 62 is configured to control the rectifier device 52 according to this measurement m of the main DC voltage supplied by the measuring element 64 in order to maintain said main DC voltage VgDc constant. The measuring element 64 and the control element 62, and therefore more generally the control unit 60, are here rotationally linked to the rotary drive element 20. They are therefore arranged in the rotating frame.One advantage is that it is not necessary to transmit the measurement signals from the rotating reference frame to the fixed reference frame. The control unit allows the main DC voltage VgDC supplied by the rectifier device 52 to be controlled and maintained constant, independently of the control of the electric motor 80 and the energy it draws from the output of the rectifier device. The system allows independent regulation of the voltage delivered by the rectifier device 52 and the supply voltage Vm of the electric motor, via two separate control circuits.

[0110] In a second embodiment illustrated in [Fig. 2], the system differs from that of [Fig. 1] by the configuration of the control unit 60'. The inverter device 46 here comprises a controlled inverter 48. In this second embodiment, the control unit 60' is configured to control said inverter device 46, and more specifically the controlled inverter 48, so as to regulate the primary AC voltage VpAc that it delivers to the primary circuit 42 of the rotating transformer 40, always so as to maintain said main DC voltage VgDc constant. The control unit 60' controls the inverter device 46 based on a measurement m' of the main DC voltage VgDC. More specifically, the measuring element 64' is configured to measure the main DC voltage VgDC. The control element 62' is configured to control the inverter device 46 based on this measurement m' of the main DC voltage provided by the measuring element 64'.

[0111] In this embodiment, the measuring element 64' is rotationally linked to the rotating drive element 20 and is located in the rotating frame. The control element 62', on the other hand, is fixed relative to a portion of the aircraft frame and is therefore located in the fixed frame.

[0112] Accordingly, the control unit 60' includes a signal transfer element 66 configured to transfer the measurement signals from the measuring element 64' to the control element 62'. The signal transfer element 66 allows the measurement signals to be transferred from the rotating reference frame to the fixed reference frame.

[0113] In this embodiment, the main DC voltage VgDc is controlled to a constant value indirectly by acting on said primary AC voltage VpAC of the primary circuit 42 of the rotating transformer 40.

[0114] In a third embodiment illustrated in [Fig. 3], the system differs from those of Figures 1 and 2 by the configuration of the control unit 60”. The inverter device 46 here comprises a controlled inverter 48. In this third embodiment, the control unit 60” is configured to control said inverter device 46 so as to regulate the primary AC voltage VpAc that it delivers to the primary circuit 42 of the rotating transformer 40, always so as to maintain said primary DC voltage VgDC constant. The control unit 60” controls the inverter device 46 according to a measurement m” of this same primary AC voltage VpAC. More precisely, the measuring element 64” is configured to measure said primary AC voltage VpAC.The control unit 62” is configured to control the inverter device 46 according to this measurement m” of the primary alternating voltage supplied by the measuring unit 64”, to maintain the main DC voltage constant.

[0115] In this third embodiment, the measuring element 64” and the control element 62”, and more generally the control unit 60”, are fixed relative to a portion of the aircraft frame and are therefore located in the fixed frame. The control element 62” is also fixed relative to a portion of the aircraft frame and is therefore located in the fixed frame.

[0116] One advantage is that it is not necessary to transmit the measurement signals from the rotating frame to the fixed frame. Furthermore, since the control element 62” is located in the fixed frame, the control is all the more reliable.

[0117] In this third embodiment, the main DC voltage VgDC is indirectly controlled to a constant value by acting on said primary AC voltage VpAc-

Claims

Demands

1. A pitch adjustment and de-icing system (10) for the blades (14) of an aircraft propeller (12), comprising a power supply (38) delivering a constant direct current (VDc) voltage, 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) rotationally linked to said rotating drive element and a rotor (84) pivoting relative to the stator and used to adjust the pitch of the aircraft propeller blades; - a de-icing device (90) for said propeller blades linked in rotation to said rotating drive element; - an inverter device (46) configured to be connected to the power supply and to deliver a primary alternating voltage (VpAc) from the constant direct current voltage delivered by said power supply; - 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 (VpAC), and a secondary circuit (44) linked in rotation to said rotating drive element and delivering a secondary alternating voltage (VsAC); - a rectifier device (52) connected to the secondary circuit and configured to deliver a main DC voltage (VgDc) from said secondary AC voltage supplied by said secondary circuit, for the electrical power supply of the electric motor and the defrosting device; - a DC / AC inverter module (72) rotationally linked to said rotating drive element and configured to provide an alternating voltage (Vm) to said stator (82) of the electric motor from the main direct voltage (VgDC) supplied by the rectifier device; - a control device (91) for the defrosting device (90) powered by said main direct current voltage (VgDC) and rotationally linked to the rotary drive element; and - a regulating unit (60,60',60") configured to maintain said main DC voltage at a constant value.

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

3. System according to claim 2, wherein said control unit (60) is configured to control said rectifier device (52) so as to regulate the main DC voltage (VgDC) 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 control 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 (VgDc) 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, wherein the control unit (60') is configured to control said inverter device (46) so as to regulate the primary AC voltage (VpAc) 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 control 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 (VgDC) delivered by the rectifier device (52), the control member being fixed relative to a portion of the aircraft frame while the measuring member is rotationally linked to said rotary drive element (20).

7. A system according to claim 2, wherein the control unit (60”) is configured to control said inverter device (46) so as to regulate the primary AC voltage (VpAC) delivered by the inverter device from a measurement (m”) of said primary AC voltage delivered by the inverter device, so as to maintain said primary DC voltage (VgDc) at a value constant.

8. System according to claim 7, wherein said control 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 (VpAc) delivered by the inverter device, the control member and the measuring member being fixed with respect to a portion of the aircraft frame.

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

10. System according to any one of claims 1 to 9, further comprising an electric motor control module (74) configured to regulate the voltage (Vm) to the stator (82) of the electric motor, from a setpoint (Ci) of the pitch of the propeller blades (14) of the aircraft and a measurement (ai) of the orientation of the propeller blades 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 (Vm) 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 propeller (14) pitch setpoint (Ci) of the aircraft propeller (12) and fixed with respect to a portion of the aircraft frame, the system further comprising at least one signal transfer element (96) configured to transfer said propeller (Ci) pitch setpoint (Ci) from said control device to the control module (74) of the electric motor (80).

13. A system according to any one of claims 1 to 12, comprising a reduction device (24) including: - a planetary gear (26) rotationally linked to said aircraft turbine; - a ring gear (32) to which said element is rotationally linked rotary drive (20); - a satellite carrier (28) fixed relative to a portion of the aircraft frame; - at least one satellite (30) mounted pivotally relative to the satellite carrier and cooperating with said planetary and said ring so that said rotating drive element is driven in rotation when the planetary is driven in rotation.

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

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