System for adjusting the pitch and de-icing the blades of an aircraft propeller, the system comprising two low-radius rotary transformers
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-03
- Publication Date
- 2026-08-13
Smart Images
Figure FR2026050105_13082026_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Title of the invention: Propeller pitch adjustment and de-icing system for an aircraft propeller comprising two low-radius rotating transformers
[0003] Technical Field
[0004] The present invention relates to systems for simultaneously adjusting the pitch of an aircraft propeller blades, considered along the longitudinal direction of said 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.
[0005] Adjusting the blade pitch is also called pitch setting. Propeller blades on turboprop engines or turbofans are generally equipped with a de-icing system using heated mats that prevent ice from forming on the blades. The invention relates to a system for performing both of these functions.
[0006] The invention also relates to an aircraft comprising such a system.
[0007] Previous technique
[0008] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by different countries. In particular, an ambitious standard applies to both new types of aircraft and those already in operation, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been actively working for several years now to contribute to the fight against climate change.
[0009] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. The Applicant takes into account the factors impacting all phases of design and development in order to obtain aeronautical components and products that are less energy-intensive, more environmentally friendly, and whose integration and use in civil aviation have moderate environmental impacts, with the aim of improving the energy efficiency of aircraft.
[0010] Sustained research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies, especially for propulsion, and finally aviation biofuels.
[0011] Within this framework, aircraft engine architectures with adjustable-pitch propellers are being developed. In traditional systems that simultaneously adjust the pitch of an aircraft's propeller blades and de-ice them, the propeller is generally attached to a rotating drive element configured to be driven by the aircraft's turbomachine. The propeller and the rotating drive element then define a rotating frame of reference, while the aircraft frame defines a fixed frame of reference.
[0012] These known systems generally include a pump driven directly by a shaft of the turbomachine's drive chain and located in the fixed frame of the aircraft's structure. This pump supplies the chambers of a hydraulic actuator that adjusts the propeller blade pitch. This actuator is located in the rotating frame of the propeller. Transferring energy from the fixed frame of the aircraft's structure to the rotating frame of the propeller, in order to power the actuator, is particularly challenging.
[0013] It is known to achieve hydraulic power transfer from an oil reservoir located in the fixed frame of reference to the actuating cylinder located in the rotating frame of reference by means of a hydraulic rotary joint called an OTB (Oil Transfer Bearing). This rotary joint is designed to be positioned concentrically with the rotating drive element and receives lines from the fixed frame of reference, which have passed through the fixed part of a reduction gear, for example, via the planet carrier of such a reduction gear. Given the concentric position of this rotary joint with the rotating drive element and the passage of these lines through the reduction gear, these systems do not allow the integration of a "low radius" rotary transformer to perform the power transfer.Indeed, such a low radius rotating transformer has an internal fixed part intended to be mounted on the planet carrier of the reducing device and an external rotating part intended to be mounted on the rotating part of the reducing device, for example the ring.
[0014] Therefore, only a rotary transformer, known as a "high-radius" rotary transformer, is compatible with such an architecture equipped with a pump in the fixed frame, provided it comprises an external fixed part connected to the aircraft frame and an internal rotating part connected to a rotating part of the reduction gear, such as the ring gear. However, such a high-radius rotary transformer is not satisfactory given the significant integration constraints it imposes. In particular, it has a large diameter if located downstream of the propeller pitch adjustment assembly and if it is integral with the aircraft frame. Furthermore, such a high-radius rotary transformer creates difficulties in accessing the fixed support.
[0015] Existing solutions for adjusting propeller blade pitch are offered using electromechanical or electrohydraulic primary actuation. These solutions eliminate the need for a supply from a reservoir within the turbomachine enclosure located in the fixed frame of reference. They therefore eliminate the need for a hydraulic rotary joint. In these solutions, which are entirely located in the rotating frame of reference, an electric motor drives the mechanical actuation or the hydraulic actuation pump, which is equipped with its own reservoir. Consequently, routing pipes that previously passed through the reduction gear is no longer necessary, and a low-radius transformer can be used for power transfer.
[0016] The electric motor for adjusting the blade pitch and the de-icing device for these systems are also located in the rotating frame. However, supplying electrical power to this rotating frame to operate these components can be complex.
[0017] It is known to power the elements of such systems arranged in the rotating frame via a brush-type commutator, which has many drawbacks. In particular, these brush-type commutators wear out quickly and require regular maintenance. Furthermore, these devices are very heavy and bulky.
[0018] Some of these systems plan to jointly power the electric motor for blade pitch adjustment and the de-icing device using a shared generator. In such a system, the generator's output voltage is regulated during current draw by the blade pitch adjustment device's electric motor to ensure the voltage required by the de-icing device. Therefore, the operation of the two devices interacts.
[0019] Another drawback of this solution is that it requires not only a voltage regulation loop in the rotating frame but also the integration of an inverter in the rotating frame for the control of the electric motor for adjusting the blade pitch.
[0020] Other systems provide for jointly powering the electric blade pitch control motor and the de-icing device via a shared rotating transformer allowing the transfer of electrical energy from an aircraft power source, located in a fixed reference point on the aircraft, to said electric motor and said de-icing device.
[0021] Document FR3131277 describes a solution for powering the electric motor and 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 specifies how to control the secondary alternating voltage delivered by the transformer based on measurements of the propeller blade orientation.
[0022] One drawback of the solution described in this document is that with each change in the electric motor's rotational speed setting, the motor draws a different amount of energy from the secondary circuit of the rotating transformer, resulting in varying current draws. This causes the secondary AC voltage supplied by the transformer to fluctuate. In other words, this secondary AC voltage is subject to variation and is particularly dependent on the operation of the electric motor. Consequently, the secondary AC voltage may prove insufficient to properly power the defrosting system. In particular, the power drawn by the defrosting system, and especially by its heating mats, may be affected, necessitating adjustments to the control of the defrosting system and the heating mats based on the available energy resources.Furthermore, in such a system, the output voltage of the rotating transformer is regulated during current draw for the electric motor of the blade pitch adjustment device, in order to guarantee sufficient voltage to power the de-icing unit. Alternatively, this voltage regulation can be achieved by controlling an inverter located in the fixed frame.
[0023] Furthermore, by adapting the de-icing system's control to its needs, the impact will be localized to the blade pitch adjustment mechanism. Indeed, regulating the voltage delivered by the rotating transformer to meet the power requirements of the de-icing system involves a significant voltage variation range. The electric motor of the pitch control device must be sized to withstand this wide voltage range, which will result in a substantial mass.
[0024] Another drawback of the solution described in this document is that it requires active and controllable rectifier devices in the rotating frame of reference to adjust the supply voltages provided to the electric motor for blade pitch control and to the de-icing system. In other words, the control loops are located in the rotating frame of reference. Furthermore, the blade pitch adjustment is performed based on blade orientation measurements taken from a measuring device located in the rotating frame of reference.
[0025] Description of the invention
[0026] One aim of the present invention is to provide a pitch adjustment and de-icing system for the blades of an aircraft propeller, remedying the aforementioned drawbacks.
[0027] To this end, the invention relates to a system for adjusting the pitch and de-icing the blades of an aircraft propeller, the aircraft comprising a power supply delivering a direct current voltage and a portion of a frame defining a fixed reference point, the system comprising:
[0028] a rotary drive element configured to be driven in rotation by a turbomachine of the aircraft;
[0029] a reducing device comprising:
[0030] a planetary gear configured to be driven in rotation by said aircraft turbomachine;
[0031] a ring to which the said rotating drive element is rotationally linked;
[0032] a satellite carrier fixed relative to said portion of aircraft frame; at least one satellite mounted pivoting relative to the satellite carrier and cooperating with said planetary gear and said ring gear so that said rotating drive element is driven into rotation when the planetary gear is driven into rotation;
[0033] a first inverter device configured to be connected to the power supply and to deliver a first primary alternating voltage from the direct voltage delivered by said power supply, said first inverter device being fixed relative to the portion of the aircraft frame;
[0034] a first low radius rotating transformer housed inside the ring of the reducing device and comprising a first primary circuit attached to the planet carrier of the reducing device so that it is fixed relative to the portion of the aircraft frame, the first primary circuit being connected to the first inverter device so that it receives the first primary alternating voltage, and a first secondary circuit linked in rotation to said rotating drive element and magnetically coupled to the first primary circuit so that it delivers a first secondary alternating voltage;
[0035] an electric motor comprising a stator rotationally linked to said rotating drive element and a rotor pivoting relative to the stator and used to adjust the pitch of the aircraft propeller blades, the electric motor being connected to the first secondary circuit of the first rotating transformer so that it is supplied by said first secondary alternating voltage;
[0036] a second inverter device configured to be connected to the power supply and to deliver a second primary alternating voltage from the direct voltage delivered by said power supply, said second inverter device being fixed relative to the portion of the aircraft frame;
[0037] a second low radius rotating transformer housed inside the ring of the reducing device and comprising a second primary circuit attached to the planet carrier of the reducing device so that it is fixed relative to said portion of the aircraft frame, said second primary circuit being connected to the second inverter device so that it receives the second primary alternating voltage, and a second secondary circuit linked in rotation to said rotating drive element and magnetically coupled to the second primary circuit so that it delivers a second secondary alternating voltage;
[0038] a de-icing device for said propeller blades carried by said rotating drive element and comprising a de-icing means, for example a set of heating mats, as well as a control module configured to control said de-icing means, said de-icing device being powered by said second secondary alternating voltage delivered by the second secondary circuit of the second rotating transformer; and
[0039] a regulating unit configured to maintain said DC voltage delivered by the power supply at a constant value.
[0040] Without limitation, the aircraft advantageously comprises a turbomachine including 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 vanes of the fan of a turbojet or turbofan. Preferably, the aircraft propeller is rotationally linked to said rotating drive element, so that it rotates at the same speed as the latter. The propeller is advantageously supported by the rotating drive element.
[0041] The power supply is advantageously a DC bus on the aircraft. Without limitation, said power supply may be a DC power network on the aircraft. This power supply is fixed relative to a portion of the aircraft frame and is therefore located in the fixed frame.
[0042] The electric motor allows for adjusting the orientation of the propeller blades around their longitudinal axes, also known as blade pitch control. The electric motor may be, but is not limited to, a synchronous or asynchronous motor. Preferably, the electric motor is configured to drive an actuation system designed to adjust the orientation of the aircraft's propeller blades. This actuation system may be, but is not limited to, electro-hydraulic (EHA), such as a pump, or electromechanical (EMA), such as a screw and nut. These actuation systems allow for adjusting the orientation of the aircraft's propeller blades along their longitudinal axis.
[0043] Without limitation, the actuation system may include an actuating cylinder configured to adjust the propeller blade pitch and an axial piston pump comprising a body rotatably linked to the aircraft propeller and configured to supply the actuating cylinder with hydraulic fluid when actuated. Such a pump may advantageously be configured in a non-flowing manner in which it does not supply the actuating cylinder when the electric motor is not powered. Such a pump advantageously comprises a stator and a rotor.
[0044] The system advantageously includes a main propeller blade pitch adjustment device comprising at least one electric motor. This main propeller blade pitch adjustment device advantageously includes the actuation system. Preferably, the electric motor is a main electric motor. The device is referred to as "main" as opposed to an "auxiliary" propeller blade pitch adjustment device, which would include an auxiliary electric motor and be configured to perform auxiliary protection functions.
[0045] According to the invention, the blade pitch adjustment is achieved by means of an electric motor. The propeller blade pitch adjustment mechanism is entirely located within the rotating frame. The invention eliminates the need for a hydraulic rotary joint, also known as an OTB (Oil Transfer Bearing). Consequently, routing pipes inside the reduction unit is unnecessary, freeing up space and allowing the use of low-radius rotary transformers housed within the reduction unit. In other words, thanks to the invention, the use of low-radius rotary transformers can be considered for transferring energy from the fixed frame to the rotating frame, not only for adjusting the propeller blade pitch but also for powering the de-icing system.
[0046] 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 an aircraft turbine, via a reduction gear. It also rotates at a lower rotational speed than the turbine. The rotary drive element is advantageously driven in rotation by a low-pressure turbine of the 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 the aircraft portion of the structure.
[0047] The satellite of the reduction gear is meshed with the planetary gear and 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 the reduction gear. The reduction gear advantageously comprises an epicyclic gear train. The reduction gear allows for easy adjustment of the rotational speed of the rotating drive element.
[0048] Advantageously, the first primary circuit and the second primary circuit of the first and second rotating transformers are fixedly mounted relative to the planet carrier of the reducing device.
[0049] By rotationally linked, it is understood that the first and second secondary circuits of the first and second rotating transformers, the defrosting device, and the stator of the electric motor rotate in the same direction as the said rotary drive element. They rotate at the same speed as this rotary drive element. Preferably, the stator of the pump in the actuation system is also rotationally linked with the rotary drive element. The rotor of the electric motor and the rotor of the pump advantageously rotate at the same speed, so that the pump is non-discharging when the electric motor is not being driven.
[0050] The first low-radius rotating transformer is configured to transfer electrical power from the power source to the electric motor for adjusting the propeller blade pitch. The second low-radius rotating transformer is configured to transfer electrical power from the power source to the de-icing device. Advantageously, the first primary and first secondary circuits of the first rotating transformer, as well as the second primary and second secondary circuits of the second rotating transformer, each comprise at least one winding.
[0051] Without limitation, the first and second rotating transformers may be of single-phase or three-phase topology. The first and second primary circuits are arranged in the fixed frame, while the first and second secondary circuits are arranged in the rotating frame.
[0052] Compared to a brushed commutator, the low-radius rotating transformers of the system according to the invention have a reduced size and weight. They are also less susceptible to wear, thus reducing maintenance requirements.
[0053] Since the first primary circuit of the first rotating transformer and the second primary circuit of the second rotating transformer are attached to the planet carrier of the reducing device, the said first and second rotating transformers are said to be "low radius", as opposed to a rotating transformer said to be "high radius".
[0054] The first primary circuit of the first rotating transformer is advantageously fixed to the planet carrier of the reduction device. The second primary circuit of the second rotating transformer is advantageously fixed to the planet carrier of the reduction device.
[0055] Preferably, the first secondary circuit of the first rotating transformer is rotationally linked to the ring gear of the reduction device, which is further preferably fixed to said ring gear. Preferably, the second secondary circuit of the second rotating transformer is rotationally linked to the ring gear of the reduction device, which is further preferably fixed to said ring gear.
[0056] It is understood that the first and second primary circuits are arranged in the fixed frame of reference while the first and second secondary circuits are arranged in the rotating frame of reference.
[0057] The first primary circuit is advantageously located inside the first secondary circuit. The second primary circuit is advantageously located inside the second secondary circuit. The first and second primary circuits are called internal, while the first and second secondary circuits are called external.
[0058] It is understood that the first and second rotating transformers are arranged internally within the ring of the reduction device, that is to say, inside an internal volume defined by said ring. The first and second rotating transformers are advantageously housed inside the reduction device. Compared to a so-called high-radius rotating transformer, the first and second low-radius rotating transformers of the system according to the invention have reduced dimensions and size.
[0059] The first secondary circuit of the first rotating transformer is advantageously connected directly to the stator of the electric motor. In other words, no component, and in particular no active component such as an active inverter or active rectifier, is connected between the first secondary circuit and the stator of the electric motor. The second secondary circuit of the second rotating transformer is advantageously connected directly to the defrosting device, preferably to the defrosting device control module. In other words, no component, and in particular no active component such as an active inverter or active rectifier, is connected between the second secondary circuit and the defrosting device.
[0060] The first inverter device allows control, from a fixed reference point, of the amplitude and frequency of the first primary AC voltage and thus indirectly of the first secondary AC voltage. The first inverter device is advantageously connected between the power supply and the first primary circuit of the first rotating transformer. It advantageously includes a DC / AC inverter. The second inverter device allows control, from a fixed reference point, of the amplitude and frequency of the second primary AC voltage and thus indirectly of the second secondary AC voltage. The second inverter device is advantageously connected between the power supply and the second primary circuit of the second rotating transformer. It advantageously includes a DC / AC inverter.The first inverter device and the second inverter device present between their input terminals the direct current voltage delivered by the power supply source.
[0061] Preferably, the first and second inverter devices are controllable or active.
[0062] The de-icing means of the de-icing device advantageously comprises a plurality of heating mats attached to the aircraft propeller blades to remove ice. The heating mats can advantageously be selectively controlled, for example, by means of switches in the control module. The de-icing device, and therefore the control module and the de-icing means, are located in the rotating frame. The control module of the de-icing device is electrically connected to the second secondary circuit of the second rotating transformer. Preferably, this control module of the de-icing device is free of an active rectifier or active inverter.
[0063] The invention therefore provides for supplying electrical power to the electric motor and the defrosting device via two separate low-radius rotating transformers. These two low-radius rotating transformers are powered from the same power source. The first inverter and the first rotating transformer are dedicated to supplying power to the electric motor for blade pitch adjustment, while the second inverter and the second rotating transformer are dedicated to supplying power to the defrosting device. Consequently, from the perspective of the rotating frame of reference, the control loop for the defrosting device and the control loop for the electric motor for blade pitch adjustment are independent. The first secondary AC voltage supplied to the electric motor is not affected by the defrosting device's operation or any current draws from the latter.Similarly, the second secondary alternating voltage supplied to the de-icing device is not impacted by the control of the electric motor for adjusting the pitch of the blades and any potential current draws from the latter.
[0064] Furthermore, unlike prior art systems in which a single rotating transformer is used to power both the de-icing device and the electric motor for adjusting the blade pitch, the invention eliminates the need to regulate the output voltage of the rotating transformers to compensate for the current demands of the de-icing device or the electric motor. Consequently, the invention eliminates the need for controllable rectifiers or inverters located in the rotating frame. Thanks to the invention, these components can be located in the fixed frame.
[0065] According to the invention, the first and second inverter devices are located in the fixed frame of reference. In other words, the control loop for the propeller blade pitch and the control loop for de-icing are both located in the fixed frame of reference. As a result, the reliability of the control of the electric motor and the de-icing device, operated respectively by the first and second inverter devices, is improved. This control in the fixed frame of reference can be implemented using more mature technologies than the control technologies generally used in the rotating frame of reference.
[0066] The electric motor and the de-icing device each draw power from the power supply, respectively via the first and second rotating transformers. The control unit maintains the DC voltage supplied by the power supply at a constant value. One advantage is ensuring the power supply to the electric motor and the de-icing device, despite potential current surges generated by the electric motor and the de-icing device at the terminals of the power supply, under the fixed reference frame. In particular, such current surges can result from variations in the electric motor's torque setpoint for adjusting the propeller blade pitch, leading to fluctuations in the power drawn by the electric motor.
[0067] Thanks to the regulating unit, the DC voltage supplied by the power source is therefore kept constant and regular. Consequently, it is not necessary to adjust the control of the first and second inverter devices according to the speed setpoint of the electric motor and the electrical energy it draws.
[0068] The regulating unit is advantageously configured to maintain said DC voltage delivered by the power supply at a constant value, based on a voltage measurement.
[0069] Preferably, the said control unit is connected between a capacitor connected to the power supply and a high-pressure or low-pressure generator. The control unit advantageously includes an inverter.
[0070] Preferably, the system further includes an electric motor control module which is fixed relative to said portion of the aircraft frame, said control module being configured to regulate the voltage to the electric motor stator, from a propeller blade pitch setpoint of the aircraft.
[0071] Preferably, the control module is configured to regulate the first secondary AC voltage supplied to the electric motor. This regulation can be achieved directly or indirectly. Even more preferably, the control module is configured to regulate the first secondary AC voltage indirectly, by regulating the first primary AC voltage. The electric motor control module is located in the fixed frame. Also, the entire control loop for adjusting the propeller blade pitch, formed by the first inverter device and the electric motor control module, is located in the fixed frame. The control module advantageously allows for adjusting the frequency and amplitude of the first secondary AC voltage supplied to the electric motor. The electric motor control module allows for adjusting the rotational speed and direction of rotation of the electric motor rotor.
[0072] Advantageously, the electric motor control module is configured to control the first inverter device in order to regulate the first primary AC voltage supplied by the latter to the first primary circuit of the first rotating transformer. One benefit is the indirect regulation of the first secondary AC voltage, achieved by regulating the first primary AC voltage from a fixed reference point. This improves the reliability of the voltage regulation and, consequently, the control of the electric motor.
[0073] The control module advantageously allows adjustment of the frequency and amplitude of the first primary AC voltage delivered by the first inverter device. It is understood that in this embodiment, the said first inverter device is controllable.
[0074] Preferably, the system further comprises a control device configured to generate the aircraft propeller blade pitch command for the electric motor control module based on a measurement of the aircraft propeller blade orientation, said control device being fixed relative to said portion of the aircraft frame. The control device is located in the fixed coordinate system.
[0075] Preferably, the system further comprises a propeller blade orientation measuring device of the aircraft configured to deliver said propeller blade orientation measurement of the aircraft, said measuring device being fixed relative to said portion of the aircraft frame.
[0076] The said measuring device advantageously comprises a plurality of sensors, each associated with one of the propeller blades.
[0077] The measuring device is configured to provide the propeller blade orientation measurement to the control device. The control device is configured to generate the aircraft propeller blade pitch command for the electric motor control module based on this measurement. The measuring device is located in the fixed frame of reference. Therefore, the accuracy of the propeller blade orientation measurement is improved. Furthermore, since the control device is also located in the fixed frame of reference, it is not necessary to transfer the measurement between the rotating and fixed frames of reference. Consequently, it is not necessary to equip the system with means to transmit measurement data from a sensor located in the rotating frame of reference. This results in improved reliability of the electric motor control for adjusting the propeller blade pitch.
[0078] Advantageously, the defrosting device control module is configured to control said defrosting means from a defrosting command issued by the control device, the system further comprising at least one signal transfer element configured to transfer said defrosting command from said control device to the defrosting device control module.
[0079] The signal transfer unit allows the defrosting instruction to be transmitted from the fixed reference point in which the control device is located to the rotating reference point in which the defrosting device control module is located.
[0080] The defrosting device control module is configured to adjust the defrosting voltage supplied by the defrosting means from the second secondary AC voltage delivered by the second rotating transformer, according to said defrosting setpoint.
[0081] Preferably, the system further includes a voltage regulation module which is fixed relative to said portion of the aircraft frame, said voltage regulation module being configured to regulate the second secondary AC voltage supplied to the de-icing device, from a voltage setpoint.
[0082] Preferably, the voltage regulation module is configured to regulate the second secondary AC voltage supplied to the defrosting device. This regulation can be achieved directly or indirectly. Even more preferably, the voltage regulation module is configured to regulate the second secondary AC voltage indirectly, by regulating the second primary AC voltage.
[0083] The voltage regulation module is located in the fixed frame. Also, the entire regulation loop for de-icing the propeller blades, consisting of the second inverter and the aforementioned voltage regulation module, is located in the fixed frame. The voltage regulation module advantageously allows adjustment of the frequency and amplitude of the secondary AC voltage supplied to the de-icing device.
[0084] Advantageously, the voltage regulation module is configured to control the second inverter device in order to regulate the second primary AC voltage supplied by the latter to the second primary circuit of the second rotating transformer. The voltage setpoint is then a setpoint for the second primary AC voltage.
[0085] One advantage is the indirect regulation of the secondary AC voltage, achieved by regulating the primary AC voltage from a fixed reference point. This improves the reliability of the voltage regulation and, consequently, the control of the defrosting system.
[0086] The voltage regulation module advantageously allows adjustment of the frequency and amplitude of the second primary AC voltage delivered by the second inverter device. It is understood that in this embodiment, the second inverter device is controllable.
[0087] According to an advantageous aspect, said control device is further configured to generate said voltage setpoint for the voltage regulation module.
[0088] Advantageously, the defrosting device control module includes a passive rectifier configured to supply a DC power supply from the second secondary AC voltage delivered by the second secondary circuit of the second rotating transformer. This rectifier advantageously includes a DC / DC converter.
[0089] Preferably, the system further includes a capacitor connected to the power supply, the first inverter device and the second inverter device each having two input terminals between which said capacitor is connected.
[0090] In other words, the first and second inverter devices are both connected to the capacitor. The capacitor is connected between the power supply and the first inverter device. The capacitor is connected between the power supply and the second inverter device. The capacitor presents the DC voltage supplied by the power supply across its terminals. The regulating unit maintains the DC voltage supplied by the power supply at a constant value, despite any current surges that may occur across the capacitor.
[0091] Advantageously, the rotary drive element defines a rotating frame of reference, the system being devoid of a controllable rectifier and controllable inverter in the rotating frame. In other words, the system does not include a controllable rectifier or controllable inverter that would be rotationally linked to the rotary drive element. One benefit is improved system reliability by reducing the power electronics located in the rotating frame and integrating them into the fixed frame.
[0092] 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.
[0093] Brief description of the drawings
[0094] The invention will be better understood upon reading the following description of an embodiment of the invention given by way of non-limiting example, with reference to the accompanying drawings, in which:
[0095] [Fig. 1] Figure 1 illustrates an embodiment of a propeller pitch adjustment and de-icing system for an aircraft propeller according to an example of the invention; and
[0096] [Fig. 2] Figure 2 is a cross-sectional view of part of a turbomachine comprising a system according to an exemplary embodiment of the invention, in the propeller area.
[0097] Description of the implementation methods
[0098] The invention relates to a system for adjusting the pitch and de-icing the blades of an aircraft propeller, said system being equipped with two rotating transformers. The rotating transformers are of the low-radius type, as will be explained below. The invention further relates to an aircraft comprising such a system.
[0099] Figure 1 shows an embodiment, given by way of non-limiting example, of a pitch adjustment and de-icing system 10 for the blades of an aircraft propeller. The aircraft includes a frame portion 102, which defines a fixed reference frame. In this non-limiting example, the aircraft includes a turbomachine 100, which may be a turbojet, a turbofan, or a turboprop. A portion of this turbomachine 100 is illustrated in Figure 1. The turbomachine includes a propeller 12 comprising a plurality of blades 14. Only one of these blades 14 is illustrated in Figure 1.
[0100] The turbomachine 100 further comprises the aircraft propeller pitch adjustment and de-icing system 10, according to the invention. The system 10 includes an electric motor 80 for adjusting the pitch of the propeller blades 14 of the propeller 12 and a de-icing device 60 for the blades, which will be described subsequently. This electric motor 80 is a primary electric motor for a primary device for adjusting the propeller blade pitch, as opposed to an auxiliary electric motor for an auxiliary device for adjusting the blade pitch configured to perform auxiliary protective functions.
[0101] The system 10 further comprises a rotary drive element 20 that is free to rotate relative to the aircraft frame portion 102 about a principal axis X. The rotary drive element 20 includes 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 gear 24. The rotary drive element 20 defines a rotating frame of reference. Subsequently, any element located in the rotating frame of reference will be considered rotationally bound to the rotary drive element 20.
[0102] The reduction gear 24 comprises an epicyclic gear train. More specifically, this reduction gear 24 includes a sun gear 26, a planet carrier 28, at least one planet gear 30 (only one of which is shown in Figure 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 the aircraft frame portion 102. The planet gear 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 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.
[0103] 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 Figure 2 showing a cross-sectional view of a part of the turbomachine 100 comprising the system 10 according to the invention, in the area of the propeller 12.
[0104] The electric motor 80 comprises a stator 82 rotatably connected to and supported by the rotary drive element 20, such that it is configured to be driven in rotation by the rotary drive element. The stator 82 of the electric motor is located in the rotating frame. The stator 82 rotates about the main axis X. The electric motor 80 further comprises a rotor 84 coupled to the stator 82 and driven in rotation about the main axis X when the electric motor is energized. The rotor 84 is located in a second rotating frame.
[0105] The system 10 further includes an actuation system 16 configured to adjust the orientation of the propeller blades 12. The actuation system 16 can be electro-hydraulic or electro-mechanical.
[0106] Referring again to Figure 1, the de-icing device 60 comprises a de-icing means 62 consisting of a plurality of heating mats, each associated with one of the blades 14 of the aircraft propeller 12. The de-icing device 60 further comprises a control module 64 configured to control said de-icing means 62. The control module 64 includes a passive rectifier device. The de-icing device 60, and therefore the de-icing means 62 and the control module 64, are rotationally linked to the rotating drive element 20, such that they are arranged in the rotating frame of reference.
[0107] Furthermore, the aircraft includes a power supply 22 forming a DC bus, consisting of a DC power network for the aircraft. This power supply 22 is configured to deliver a DC voltage VDC. The system 10 includes a capacitor 23. The system 10 further includes a control unit 70 connected between the capacitor 23 and the power supply 22. This control unit 70 is configured to maintain the DC voltage delivered by the power supply at a constant value. The system also includes a first rotary transformer 34 of the low-radius transformer type, housed within the ring 32 of the reduction device 24. The first rotary transformer 34 includes a first primary circuit 36 comprising at least one winding and a first secondary circuit 38 comprising at least one winding.Since the first rotating transformer 34 is of the low-radius type, the first primary circuit 36 is fixed to the planet carrier 28 of the reduction device, so that it is fixed relative to the aircraft frame portion 102 and is therefore located in the fixed frame. It is carried by a fixed support 21, which is attached to the planet carrier 28 of the reduction device 24. The first secondary circuit 38 is external to the first primary circuit 36 and is fixed to the ring gear 32 of the reduction device. It is rotationally linked to the rotating drive element 20 and is located in the rotating frame. The first secondary circuit 38 is magnetically coupled to the first primary circuit 36. The first secondary circuit 38 is directly connected to the stator 82 of the electric motor 80.
[0108] The system 10 also includes a first inverter device 40 of the fixed duty cycle type. The first inverter device 40 is electrically connected to the first primary circuit 36 of the first rotating transformer 34. The first inverter device 40 is also connected to the power supply 22 so that it receives the said DC voltage VDC. More specifically, the first inverter device 40 has two input terminals between which the said capacitor 23 is connected.
[0109] The first inverter device 40 is configured to deliver a first primary AC voltage VPACI to the first primary circuit 36 of the first rotating transformer 34 from the DC voltage VDC supplied by the power supply source 22.
[0110] The first rotating transformer 34 is configured to transfer electrical energy from the power supply 22, and therefore from the fixed frame, to the electric motor 80, and thus to the rotating frame. The first secondary circuit 38 of the first rotating transformer 34 is magnetically coupled to the first primary circuit 36, so that it delivers a first secondary AC voltage VSACI to the stator 82 of the electric motor 80, based on the first primary AC voltage VPACI received by the first primary circuit 36. The first secondary circuit 38 presents said first secondary AC voltage VSACI across its terminals.
[0111] The energized stator 82 drives the rotation of the electric motor's rotor 84. The electric motor's rotor 84 drives the actuation system 16. This system is configured to convert the rotational motion of the rotor 84 into a translational motion of a cylinder (electrohydraulic system) or a nut (electromechanical system). This translational motion is then converted into a rotational motion of the propeller blades 14 around their longitudinal axis via a connecting rod and crank mechanism 18.
[0112] The system 10 also includes a control module 42 for the electric motor 80. This control module 42 is configured to control the first inverter device 40 in order to regulate the first primary AC voltage VPACI delivered by the latter, based on a setpoint Ci for the pitch of the propeller 12 of the aircraft. The control module 42 thus indirectly regulates the first secondary AC voltage VPACI supplied by the first rotating transformer 34 to the electric motor 80. The control module 42 is fixed relative to the portion of the aircraft frame 102, so that it is positioned in the fixed coordinate system.
[0113] The system 10 further includes a measuring device 46 for the orientation of the propeller blades 14 of the aircraft. This measuring device 46 comprises a plurality of sensors associated with the propeller blades 14. The measuring device 46 is fixed relative to the aircraft frame portion 102, so that it is positioned in the fixed frame. It is configured to provide a measurement ai of the orientation of the propeller blades, considered along the longitudinal axis of said blades.
[0114] The system 10 also includes a control device 44 configured to generate the propeller pitch setpoint Ci for the aircraft propeller blades 14, based on the measurement ai of the aircraft propeller blade orientation provided by the measuring device 46. The control device 44 transmits this propeller pitch setpoint Ci for the propeller blades 14 to the electric motor control module 42. The control device 44 is fixed relative to the aircraft frame portion 102, so that it is positioned in the fixed coordinate system.
[0115] The system also includes a second rotating transformer 50 of the low-radius type, housed inside the ring 32 of the reduction unit 24. The second rotating transformer 50 comprises a second primary circuit 52 including at least one winding and a second secondary circuit 54 including at least one winding. Since the second rotating transformer 50 is of the low-radius type, the second primary circuit 52 is fixed to the planet carrier 28 of the reduction unit, so that it is fixed relative to the aircraft frame portion 102 and is therefore located in the fixed frame. As illustrated in Figure 2, it is fixed to a support attached to the planet carrier 28 of the reduction unit 24. The second secondary circuit 54 is external to the second primary circuit 52 and is fixed to the ring 32 of the reduction unit. It is rotationally linked to the rotary drive element 20 and is located in the rotating frame.The second secondary circuit 54 is magnetically coupled to the second primary circuit 52. The second secondary circuit 54 is directly connected to the control module 64 of the defrosting device 60.
[0116] The system 10 further includes a second inverter device 56 electrically connected to the second primary circuit 52 of the second rotating transformer 50. The second inverter device 56 is also connected to the power supply 22 so that it also receives the said DC voltage VDC. More specifically, the second inverter device 56 has two input terminals between which the said capacitor 23 is connected.
[0117] The second inverter device 56 is configured to provide a second primary AC voltage VPACZ to the second primary circuit 52 of the second rotating transformer 50 from the constant DC voltage VDC supplied by the power supply source 22.
[0118] The second rotating transformer 50 is configured to transfer electrical energy from the power supply 22, and therefore from the fixed reference frame, to the de-icing device 60, and thus to the rotating reference frame. The second secondary circuit 54 of the second rotating transformer 50 is magnetically coupled to the second primary circuit 52, so that it delivers a second secondary AC voltage VSACZ to the control module 64 of the de-icing device 60, from the second primary AC voltage VPACZ received by the second primary circuit 52. The second secondary circuit 54 presents said second secondary AC voltage VsAcz at its terminals. The system also includes a voltage regulation module 58 which is fixed relative to said portion of the aircraft frame 102, and is therefore located in the fixed reference frame.The voltage regulation module 58 is configured to regulate the second secondary AC voltage VSACZ supplied to the defrosting device 60. To do this, the voltage regulation module is configured to control the second inverter device 56 in order to regulate the second primary AC voltage VPACZ supplied by the latter to the second primary circuit 52 of the second rotating transformer 50, from a voltage setpoint C2.
[0119] This voltage setpoint C2 is generated and supplied by the control device 44. This voltage setpoint C2 is determined in order to allow the regulation of the second primary AC voltage VPAC2, and indirectly the second secondary AC voltage VSAC2, to a chosen value.
[0120] The passive rectifier device of the control module 64 of the defrosting device 60 is configured to supply a defrosting voltage V to the defrosting means 62 acontinues from said second secondary alternating voltage VSAC2 which it receives, according to a defrosting setpoint C3. This voltage setpoint C3 is generated and supplied to the control module 64 by the control device 44.
[0121] The system further includes a signal transfer unit 66 configured to transfer said defrosting command C3 from said control device 44, located in the fixed frame, to the control module 64 of the defrosting device, located in the rotating frame.
[0122] The control unit 70 makes it possible to maintain the DC voltage delivered by the power supply 22 at a constant value despite the current demands generated by the electric motor 80 and the defrosting device 60.
[0123] According to the invention, the first rotating transformer 34 is dedicated to powering the electric motor 80, while the second rotating transformer 50 is dedicated to powering the defrosting device. From the perspective of the rotating frame of reference, the control loop for the defrosting device and the control loop for the electric motor for adjusting the blade pitch are independent.
Claims
Demands 1. System (10) for adjusting the pitch and de-icing the blades (14) of a propeller (12) of an aircraft, the aircraft comprising an electrical power supply (22) delivering a direct current (DC) voltage and a portion of a frame (102) defining a fixed reference frame, the system comprising: a rotary drive element (20) configured to be driven in rotation by a turbomachine of the aircraft; a reducing device (24) comprising: a planetary gear (26) configured to be driven in rotation by said turbomachine of the aircraft; a ring (32) to which the said rotating drive element (20) is rotationally linked; a satellite carrier (28) fixed relative to said portion of the aircraft frame (102); 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 into rotation when the planetary is driven into rotation; a first inverter device (40) configured to be connected to the power supply and to deliver a first primary alternating voltage (VPACI) from the direct voltage delivered by said power supply, said first inverter device being fixed with respect to the portion of the aircraft frame; a first rotating transformer (34) with a low radius housed inside the ring of the reducing device and comprising a first primary circuit (36) attached to the satellite carrier of the reducing device so that it is fixed relative to the portion of the aircraft frame, said first primary circuit being connected to the first inverter device (40) so that it receives the first primary alternating voltage (VPACI), and a first secondary circuit (38) rotationally linked to said rotating drive element and magnetically coupled to the first primary circuit so that it delivers a first secondary alternating voltage (VSACI); an electric motor (80) comprising a stator (82) linked in rotation to said rotating drive element and a rotor (84) pivoting relative to the stator and used to adjust the pitch of the propeller blades of the aircraft, the electric motor being connected to the first secondary circuit of the first rotating transformer so that it is supplied by said first secondary alternating voltage; a second inverter device (56) configured to be connected to the power supply and to deliver a second primary alternating voltage (VPACZ) from the direct voltage delivered by said power supply, said second inverter device being fixed with respect to the portion of the aircraft frame; a second low-radius rotating transformer (50) housed inside the ring of the reducing device and comprising a second primary circuit (52) integral with the planet carrier of the reducing device so that it is fixed relative to said portion of the aircraft frame, the second primary circuit being connected to the second inverter device (56) so that it receives the second primary alternating voltage (VPACZ), and a second secondary circuit (54) rotationally linked to said rotating drive element and magnetically coupled to the second primary circuit so that it delivers a second secondary alternating voltage (VSACZ); a de-icing device (60) for said propeller blades carried by said rotating drive element and comprising a de-icing means (62), for example a set of heating mats, and a control module (64) configured to control said de-icing means, said de-icing device being powered by said second secondary alternating voltage delivered by the second secondary circuit of the second rotating transformer; and a regulating unit (70) configured to maintain said DC voltage delivered by the power supply at a constant value.
2. System according to claim 1, further comprising a control module (42) of the electric motor (80) which is fixed relative to said portion of the aircraft frame (102), said control module being configured to regulate the voltage (VSACI) to the stator (82) of the electric motor, from a setpoint (Ci) of the pitch of the blades (14) of the propeller (12) of the aircraft.
3. System according to claim 2, wherein the control module (42) of the electric motor (80) is configured to control said first inverter device (40) in order to regulate the first primary alternating voltage (VPACI) supplied by the latter to the first primary circuit (36) of the first rotating transformer (34).
4. System according to claim 2 or 3, further comprising a control device (44) configured to generate said propeller (12) pitch setpoint (Ci) for said control module (42) of the electric motor (80), from a measurement (ai) of the orientation of the propeller blades of the aircraft, said control device being fixed with respect to said portion of the aircraft frame (102).
5. System according to claim 4, wherein the control module (64) of the defrosting device (60) is configured to control said defrosting means (62) from a defrosting command (C3) delivered by the control device (44), the system further comprising at least one signal transfer element (66) configured to transfer said defrosting command (C3) from said control device (44) to the control module (64) of the defrosting device (60).
6. System according to any one of claims 1 to 5, further comprising a voltage regulation module (58) which is fixed relative to said portion of the aircraft frame (102), said voltage regulation module being configured to regulate the second secondary AC voltage (VSACZ) supplied to the de-icing device (60), from a voltage setpoint (C2).
7. System according to claim 6, wherein the voltage regulation module (58) is configured to control said second inverter device (56) in order to regulate the second primary alternating voltage (VPACZ) supplied by the latter to the second primary circuit (52) of the second rotating transformer (50).
8. System according to claim 4 or 5 taken in combination with claim 6 or 7, wherein said control device (44) is further configured to generate said voltage setpoint (C2) for the voltage regulation module (58).
9. System according to any one of claims 1 to 8, wherein the rotary drive element (20) defines a rotating frame, said system (10) being devoid of a controllable rectifier and controllable inverter in the rotating frame.
10. 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 9.