System for the pitch-adjustment and de-icing of the blades of a propeller of an aircraft comprising an auxiliary actuating device

Abstract

Disclosed is a system for the pitch-adjustment and de-icing of the blades (14) of an aircraft propeller (12), having a reduction device (24) comprising a sun gear (26); a ring gear (32) rigidly connected to a first rotary drive element (20); a planet carrier (28) and a planet gear (30); a main actuating device (46) driven by a main electric motor (40) powered by a main power-supply device (68, 68'); an auxiliary actuating device (56) driven by an auxiliary electric motor (50); a de-icing device (60) for de-icing the blades; an auxiliary inverter device (86) configured to deliver an auxiliary primary AC voltage (VpAC1); and an auxiliary rotating transformer (80) comprising an auxiliary primary circuit (82) secured to the planet carrier and an auxiliary secondary circuit (84) and delivering an auxiliary secondary AC voltage (VsAC1); and a switching module (90) configured to selectively control the power supply to said de-icing means or to said auxiliary electric motor (50).

Description

[0001] Description

[0002] Title of the invention: Propeller pitch adjustment and de-icing system for an aircraft propeller comprising an auxiliary actuation device

[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. More specifically, the invention relates to such systems comprising a primary actuation device configured to adjust the orientation of the propeller blades, and an auxiliary actuation device providing auxiliary protective functions, such as feathering. These protective functions must be ensured, in particular, in the event of overspeed, engine stall, failure of the FADEC control system, or leaks from the rotating oil transfer device or lines.Such an auxiliary actuation device is configured to bring the propeller blades into a feathered configuration, in which they exhibit reduced drag, when one or more of the aforementioned defects are encountered. The auxiliary actuation device also ensures the exit from said feathered configuration. The invention also relates to an aircraft comprising such a system.

[0005] Previous technique

[0006] Systems are known that include a main electric motor driving a main actuation device configured to adjust the pitch of the fan blades of a turbofan or the propeller blades of a turboprop, an auxiliary electric motor driving an auxiliary actuation device providing the functions of blade protection and feathering, and a device for de-icing these blades.

[0007] Propeller blades equipping turboprops or turbofans are generally equipped with a means of de-icing by heating mats which prevent the formation of ice on the blades.

[0008] The aircraft propeller is located in a rotating frame. The main electric motor for adjusting the blade pitch, the auxiliary electric motor for driving the auxiliary actuation device, and the de-icing system are also located in this rotating frame. Supplying electrical power to this rotating frame to supply these components can be complex.

[0009] It is known that the main and auxiliary electric motors, or the defrosting system, are powered in the rotating bearing by means of brush-type commutator devices, which have numerous drawbacks. In particular, these brush-type commutator devices wear out quickly and require regular maintenance. Furthermore, these devices are very heavy and bulky.

[0010] Some systems provide a shared power supply for both the main electric motor used to adjust the blade pitch and the de-icing mechanism of such a system. In this system, the generator's output voltage is regulated during current draw by the main electric motor, which drives the main actuation device, thus ensuring the required voltage for the de-icing mechanism. Therefore, the operation of both devices interacts.

[0011] Another drawback of this solution is that it requires not only a voltage regulation loop in the rotating frame but also an inverter in the rotating frame for driving the main electric motor.

[0012] Other systems provide for jointly powering the main electric motor for blade pitching 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.

[0013] Document FR3131277 describes a solution for powering both the electric motor and the de-icing device of such a system via a single rotating transformer. This transformer comprises a primary circuit connected to a power supply and a secondary circuit connected to both 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 proposes controlling the secondary alternating voltage delivered by the transformer based on propeller blade orientation measurements. One drawback of the solution described in this document is that with each change in the electric motor's rotational speed setpoint, the electric motor draws a different amount of energy from the transformer's secondary circuit, resulting in varying current draws on the transformer.This results in variations in the secondary AC voltage supplied by the transformer. 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 unit, and especially by its heating mats, may be affected, necessitating adjustments to the control of the defrosting unit and the heating mats based on the available energy resources.

[0014] In such a system, the output voltage of the rotating transformer is regulated during current draws for the electric motor to ensure the voltage required by the defrosting device. This voltage regulation can be achieved by controlling an inverter in the fixed reference frame.

[0015] Furthermore, by adapting the defrosting system's control to its specific needs, the impact will be localized to the step control device. Indeed, regulating the voltage supplied by the rotating transformer to meet the power requirements of the defrosting system involves a significant voltage variation range. The electric motor of the step control device must be sized to withstand this wide voltage range, which will result in a substantial mass.

[0016] Another drawback of the solution described in this document is that it requires an inverter in the rotating frame, as is the case for the previously described solution using a shared generator, in order to adjust the supply voltages provided to the electric motor for blade pitch control and de-icing. The blade pitch adjustment is further performed based on blade orientation measurements taken from a measuring device located in the rotating frame.

[0017] Finally, this document does not provide a solution for powering, in the rotating frame, an auxiliary electric motor to drive an auxiliary actuation device that would perform the protection functions. Description of the invention

[0018] 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.

[0019] 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 an electrical power supply delivering a direct current voltage and a portion of the frame defining a fixed reference frame, the system comprising: at least one first rotary drive element carrying the propeller; a reduction device comprising: a planet gear configured to be driven in rotation by a turbomachine of the aircraft; a ring gear fixed to the first rotary drive element; a planet carrier fixed relative to said portion of the aircraft frame; at least one planet gear mounted pivoting relative to the planet carrier and cooperating with said planet gear and said ring gear so that said first rotary drive element is driven in rotation when the planet gear is driven in rotation; a main actuation device configured to adjust the orientation of the propeller blades;a main electric motor comprising a main stator rotationally linked to said first rotating drive element and a main rotor pivoting relative to the main stator and configured to drive the main actuation device; a main power supply device configured to supply the main electric motor with electrical power and comprising at least one rotating part rotationally linked to the first rotating drive element; an auxiliary actuation device configured to selectively bring the propeller blades into a so-called feathered configuration in which they exhibit reduced drag, or into a so-called unfeathered configuration in which said blades extend transversely to a longitudinal direction of the aircraft;an auxiliary electric motor having an auxiliary stator rotationally linked to the first rotary drive element and an auxiliary rotor movable in rotation relative to the auxiliary stator and configured to drive the auxiliary actuation device in order to bring the propeller blades into the feathered or unfeathered configuration; a de-icing device for said propeller blades carried by said first rotary drive element and comprising a de-icing means including a set of heating mats, and a control module configured to control said de-icing means, said control module including an auxiliary rectifier device and a set of mat switches allowing the heating mats to be selectively controlled;an auxiliary inverter device configured to be connected to the power supply and to deliver an auxiliary primary alternating voltage from the direct voltage delivered by said power supply, said auxiliary inverter device being fixed relative to the portion of the aircraft frame; an auxiliary rotating transformer having an auxiliary primary circuit integral with the planet carrier of the reduction device and electrically connected to said auxiliary inverter device so that it receives said auxiliary primary alternating voltage, and an auxiliary secondary circuit rotationally linked to said first rotating drive element and magnetically coupled to the auxiliary primary circuit so that it delivers an auxiliary secondary alternating voltage used to electrically supply the de-icing means and the auxiliary electric motor;and a switching module configured to selectively control the electrical power supply: to said defrosting means with a DC voltage supplied by said auxiliary rectifier device from said auxiliary secondary AC voltage; or to said auxiliary electric motor with said auxiliary secondary AC voltage or with a DC voltage obtained from said auxiliary secondary AC voltage.

[0020] 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's propeller is rotationally linked to said first rotary drive element, so that it rotates at the same speed as the latter. The propeller is advantageously supported by the first rotary drive element.

[0021] 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.

[0022] The main electric motor drives the main actuation device to adjust the orientation of the propeller blades around their longitudinal axes, also known as blade pitch. The main electric motor ensures blade pitch during normal operation, barring any faults or malfunctions. The main electric motor may be, but is not limited to, a synchronous or asynchronous motor.

[0023] By way of example, the main actuation device may be electro-hydraulic (EHA), comprising, for example, a reversible fixed-displacement pump, or electromechanical (EMA), comprising, for example, a drive screw and nut. The main actuation device allows adjustment of the propeller blades of the aircraft in question along the longitudinal direction of said blades.

[0024] The auxiliary electric motor drives the auxiliary actuation device to ensure feathering, particularly in the event of faults such as overspeed, FADEC control system failure, or leaks from the rotating oil transfer device or piping. This feathering configuration is well known to those skilled in the art. The auxiliary electric motor can be, but is not limited to, an AC or DC motor.

[0025] The auxiliary actuation device allows the propeller blades to be rotated around their longitudinal axes to bring them into or out of the feathered configuration. The auxiliary actuation device also provides system protection functions.

[0026] Without limitation, the auxiliary actuation device may be electrohydraulic (EHA) or electromechanical (EMA). Advantageously, the auxiliary actuation device is electrohydraulic. Preferably, the auxiliary actuation device includes a bidirectional pump. Even more preferably, the auxiliary actuation device includes an actuating cylinder configured to adjust the propeller blade pitch and a bidirectional pump comprising a body rotatably linked to the aircraft propeller and configured to supply the actuating cylinder with hydraulic fluid when actuated.

[0027] The defrosting device, and more specifically the auxiliary rectifier device, receives the said auxiliary secondary alternating voltage as input.

[0028] The de-icing means of the de-icing system comprises a plurality of heating mats attached to the aircraft's propeller blades, enabling the removal of ice. The heating mats are selectively controlled by means of mat switches and are powered by a DC voltage supplied by the auxiliary rectifier.

[0029] The auxiliary rectifier is advantageously configured to supply the DC voltage for the defrosting means according to a defrosting setpoint. Preferably, the system includes a computer configured to supply the defrosting setpoint. Preferably, the system includes a signal transfer element configured to transfer the defrosting setpoint from the computer to the auxiliary rectifier, and thus from the fixed reference point to the rotating reference point.

[0030] The reduction gear is configured to drive the first rotary drive element at a speed lower than the rotational speed at which the turbomachine drives the planetary gear. This planetary gear is meshed with both the planetary gear and the ring gear. The ring gear rotates at a reduced speed relative to the planetary gear's rotational speed, according to the reduction ratio of the reduction gear. This reduction ratio is less than 1. The reduction gear advantageously comprises an epicyclic gear train. The reduction gear allows for easy adjustment of the rotational speed of the first rotary drive element.

[0031] The first rotary drive element is advantageously configured to rotate about a main axis. The first rotary drive element may include a drive shaft. The first 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 rotational speed of this turbine. The first rotary drive element is advantageously driven in rotation by a low-pressure turbine of the aircraft turbomachine, via a reduction gear. The first rotary drive element defines a first rotating frame of reference, considered as opposed to a fixed frame of reference corresponding to the frame of the aircraft portion of the structure.

[0032] By rotationally linked, it is understood that the rotating part of the main power supply, the auxiliary secondary circuit of the auxiliary rotating transformer, the defrosting device, the main stator of the main electric motor, and the auxiliary stator of the auxiliary electric motor describe the same rotational motion as the first rotary drive element. They rotate at the same speed as this first rotary drive element. It is understood that the control module and the defrosting means of the defrosting device are located within the rotating frame. Preferably, the rotating part of the main power supply, the auxiliary secondary circuit of the auxiliary rotating transformer, the defrosting device, the main stator of the main electric motor, and / or the auxiliary stator of the auxiliary electric motor are supported by the first auxiliary drive element.

[0033] According to a first advantageous variant, the main power supply device is connected to the power supply and configured to transfer electrical energy from the power supply to the main electric motor, for example, via an inverter located in the fixed frame. In this variant, the main power supply device may, but is not limited to, include a rotating transformer, for example, a low-radius rotating transformer. The supply voltage regulation of the main electric motor is then advantageously achieved by controlling an inverter in the fixed frame.

[0034] According to another advantageous variant, the main power supply is configured to generate electrical power which it then supplies to the main electric motor. In this variant, the main power supply may, but is not limited to, include a generator configured to generate electrical power, for example, a differential-speed generator. The voltage supplied to the main electric motor is then advantageously regulated by driving the main stator of the main electric motor in the rotating frame. The auxiliary rotating transformer is configured to transfer electrical power from the power supply to the de-icing means and to the auxiliary electric motor.In other words, the auxiliary rotary transformer powers the auxiliary electric motor for feathering or unfeathered configuration, or alternatively, the defrosting unit. The auxiliary rotary transformer is therefore shared, supplying power to both the defrosting unit and the auxiliary electric motor. The auxiliary rotary transformer is dedicated to supplying power to both the auxiliary electric motor and the defrosting unit. However, the auxiliary electric motor and the defrosting unit are not powered simultaneously, but selectively via a control system controlled by the switching module.

[0035] Advantageously, the auxiliary primary circuit and the auxiliary secondary circuit of the auxiliary rotating transformer each comprise at least one winding. Without limitation, the auxiliary rotating transformer may be of single-phase or three-phase topology.

[0036] Since the auxiliary primary circuit of the auxiliary rotating transformer is integral with the planet carrier of the reduction device, this rotating transformer is called a "low radius" transformer, as opposed to rotating transformers called "high radius" transformers. The auxiliary primary circuit of the auxiliary rotating transformer is advantageously fixed to the planet carrier.

[0037] It is understood that the auxiliary primary circuit of the auxiliary rotating transformer is fixed relative to the aircraft frame. The auxiliary primary circuit is located in the fixed frame defined by the aircraft frame, while the auxiliary secondary circuit is located in the first rotating frame.

[0038] Compared to a brushed commutator, the auxiliary rotating transformer of the system according to the invention has a reduced size and weight. It is also less susceptible to wear, thus reducing maintenance requirements.

[0039] The switching module allows for the exclusive control of either the auxiliary electric motor's power supply or the defrosting unit's power supply. In other words, the auxiliary electric motor and the defrosting unit are not powered simultaneously. However, they are both supplied from the same auxiliary secondary AC voltage provided by the auxiliary rotary transformer. When the auxiliary electric motor needs to be powered, the defrosting unit no longer needs to operate, thus enabling separate power supply for the auxiliary electric motor and the defrosting unit, while still utilizing the same auxiliary rotary transformer.

[0040] The switching module is advantageously configured to assume a first configuration in which it controls the power supply to the defrosting unit with the DC voltage provided by the auxiliary rectifier device from the auxiliary secondary AC voltage. In this first configuration, the auxiliary electric motor is not supplied with electrical energy. The switching module is advantageously configured to assume a second configuration in which it controls the power supply to the auxiliary electric motor with a DC voltage obtained from the auxiliary secondary AC voltage or directly from the auxiliary secondary AC voltage. In this second configuration, the defrosting unit is not supplied with electrical energy.

[0041] The switching module allows the auxiliary electric motor to be powered either directly by the auxiliary secondary AC voltage supplied by the auxiliary rotating transformer, or by a voltage derived from the auxiliary secondary AC voltage, for example, a DC voltage supplied by a rectifier device. This DC voltage is advantageously obtained by rectifying the auxiliary secondary AC voltage, for example, using a rectifier device. Without limitation, the DC voltage may be supplied by the auxiliary rectifier device of the defrosting system control module, from the auxiliary secondary AC voltage.

[0042] Preferably, the auxiliary secondary circuit of the auxiliary rotating transformer is connected to the defrosting device, or even more preferably to the defrosting device control module.

[0043] By way of example, the switching module may be connected, on the one hand, between the auxiliary secondary circuit of the auxiliary rotary transformer and the auxiliary rectifier of the defrosting device control module, and on the other hand, between said auxiliary secondary circuit of the auxiliary rotary transformer and the auxiliary electric motor. Alternatively, the switching module may be connected, on the one hand, between said auxiliary rectifier and the defrosting device, and on the other hand, between the auxiliary rectifier and the auxiliary electric motor. The auxiliary secondary circuit of the auxiliary rotary transformer is then electrically connected to said auxiliary rectifier.

[0044] Preferably, the defrosting device control module includes said switching module.

[0045] The auxiliary inverter allows control, from a fixed reference point, of the amplitude and frequency of the auxiliary primary AC voltage and the amplitude and frequency of the auxiliary secondary AC voltage, and thus indirectly of the amplitude of the voltage delivered by the auxiliary rectifier. The auxiliary inverter is advantageously connected between the power supply and the auxiliary primary circuit of the auxiliary rotating transformer. It advantageously includes a DC / AC inverter. Preferably, the auxiliary inverter is controllable or active.

[0046] The invention provides for selectively powering, on the one hand, the auxiliary electric motor or the defrosting device via a dedicated auxiliary rotating transformer, and on the other hand, the main electric motor via its dedicated main power supply. The defrosting device and the auxiliary electric motor are selectively powered from the same power source. The same voltage is used as the power supply for both the defrosting device and the auxiliary electric motor. The main electric motor is powered independently via the main power supply. The main power supply is dedicated to powering the main electric motor.

[0047] According to the invention, the auxiliary rotary transformer for supplying electrical power to the defrosting unit and the auxiliary electric motor is shared. The defrosting unit and the auxiliary electric motor are powered from the same AC voltage at the output of the auxiliary rotary transformer, namely the auxiliary secondary AC voltage, the amplitude of which is controlled in the fixed reference frame, for example, by controlling the auxiliary inverter device. In other words, the auxiliary inverter device located in the fixed reference frame allows the DC or AC voltage supplied to the auxiliary electric motor to be modulated without affecting the operation of the defrosting unit when the auxiliary drive device is functional.

[0048] Thanks to the invention, it is not necessary to place an inverter in the rotating frame to power the auxiliary electric motor, which is a significant advantage. Therefore, sharing the auxiliary rotating transformer to power both the defrosting unit and the auxiliary electric motor is a relevant solution since they operate independently. One benefit is a reduction in the number of components, as well as the system's weight and cost, and the resources required.

[0049] The invention makes it possible to keep the control loop of the defrosting means and the auxiliary electric motor in the fixed reference frame, which improves the reliability of the control.

[0050] Furthermore, from the perspective of the rotating frame of reference, the control loop for controlling and supplying electrical power to the de-icing system and the auxiliary electric motor is independent of the control loop and supplying electrical power to the main electric motor for adjusting the propeller blade pitch. The main secondary AC voltage supplied to the main electric motor is not affected by the selective control of the de-icing system and the auxiliary electric motor, nor by any current draws from these motors. Similarly, the auxiliary secondary AC voltage used to selectively power the de-icing system and the auxiliary electric motor is not affected by the control of the main electric motor for adjusting the blade pitch, nor by any current draws from the latter.

[0051] Also, unlike systems in which a single rotating transformer is used to power both the de-icing unit and a main electric motor for adjusting the blade pitch, the invention eliminates the need to regulate the output voltage of the rotating transformer(s) in the rotating frame to compensate for the current demands of the de-icing unit or the main electric motor. Consequently, the invention eliminates the need for controllable rectifiers or inverters located in the rotating frame. These can be located in the fixed frame.

[0052] The invention allows for the arrangement of the control loop for propeller blade pitch control and the control loop for de-icing power regulation in the fixed frame of reference. This results in improved reliability of the control of the main electric motor and the de-icing system. 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.

[0053] Preferably, the system further comprises a computer fixed relative to the said portion of the aircraft frame, the computer being configured to generate one or more control setpoints for controlling the auxiliary inverter, the de-icing device, and / or the main power supply. The computer is located in the fixed frame. It is advantageously configured to generate the setpoint(s) based on voltage measurements taken in the rotating frame or on measurements of the propeller blade orientation. It is advantageously configured to provide control setpoints to a controller of said main power supply.

[0054] Advantageously, the system further includes an auxiliary regulator which is fixed relative to said portion of the aircraft frame, said auxiliary regulator being configured to control said auxiliary inverter device in order to regulate the auxiliary primary AC voltage supplied by the latter to the auxiliary primary circuit of the auxiliary rotating transformer, from an auxiliary voltage setpoint, the computer preferably being configured to generate said auxiliary voltage setpoint for said auxiliary regulator, from a measurement of the auxiliary primary AC voltage supplied to the auxiliary rotating transformer or from a measurement of the auxiliary secondary AC voltage delivered by said auxiliary rotating transformer or from a measurement of the DC voltage supplied by said auxiliary rectifier device of the de-icing device control module.The auxiliary regulator is configured to control the auxiliary inverter device in order to regulate the auxiliary primary AC voltage, the auxiliary secondary AC voltage, or the DC voltage delivered by the auxiliary rectifier device to a setpoint value. It is understood that in this embodiment, the auxiliary inverter device is controllable. The auxiliary regulator indirectly regulates the auxiliary secondary AC voltage supplied by the auxiliary rotating transformer, which is used either to power the defrosting unit or to power the auxiliary electric motor. The auxiliary regulator advantageously allows adjustment of the amplitude of the auxiliary secondary AC voltage supplying the auxiliary electric motor.Preferably, but not exclusively, the auxiliary controller allows adjustment of the rotational speed of the auxiliary rotor of the auxiliary electric motor, when the latter is of the asynchronous type. The direction of rotation of the auxiliary electric motor is advantageously adjusted by a set of switches in the control module at the output of the auxiliary rectifier device.

[0055] The auxiliary regulator is located in the fixed frame. Also, the entire control loop for controlling the auxiliary electric motor and feathering or unfeathering the propeller blades, formed by the auxiliary inverter and the aforementioned auxiliary regulator, is located in the fixed frame. The reliability of the voltage regulation, and therefore of the control of the auxiliary electric motor, is improved.

[0056] The measurement of the auxiliary primary AC voltage is taken in the fixed reference frame, which improves its reliability and therefore the reliability of the control.

[0057] According to an advantageous embodiment, the auxiliary electric motor is an AC motor, for example, an asynchronous motor, with the switching module connected between the auxiliary electric motor and the auxiliary secondary circuit of the auxiliary rotating transformer, such that the auxiliary electric motor is directly supplied by the auxiliary secondary AC voltage. Advantageously, according to this embodiment, no active component such as an active inverter or active rectifier is connected between the auxiliary secondary circuit and the auxiliary stator of the auxiliary electric motor. In this configuration, the same auxiliary secondary AC voltage is supplied to both the auxiliary electric motor and the defrosting device.

[0058] Preferably, no component is connected between the auxiliary secondary circuit and the switching module, nor between the switching module and the auxiliary stator of the auxiliary electric motor.

[0059] In the case of an asynchronous type auxiliary electric motor, the direction of rotation of the auxiliary rotor is advantageously adjusted by controlling the auxiliary inverter device.

[0060] According to another advantageous embodiment, the auxiliary electric motor is a DC motor, and the switching module is connected between the auxiliary rectifier and the auxiliary electric motor such that it is configured to drive the power supply to the auxiliary electric motor with a DC voltage delivered by the auxiliary rectifier from the auxiliary secondary AC voltage supplied by the auxiliary secondary circuit of the auxiliary rotating transformer. According to this embodiment, the auxiliary rectifier is configured to deliver a DC voltage for selectively supplying power to either the auxiliary electric motor or the defrosting means, depending on the configuration of the switching module. Preferably, the switching module is also connected between the auxiliary rectifier and the defrosting means.

[0061] The auxiliary rectifier device is advantageously a passive or non-controllable rectifier device.

[0062] Advantageously, the switching module further includes a set of auxiliary switches configured to be selectively operated in order to adjust the direction of the electric current supplied to the auxiliary electric motor, so as to adjust its direction of rotation.

[0063] When activated, the auxiliary switches reverse the power supply to the terminals of the auxiliary electric motor in order to cause the propeller blades to be put into feathering configuration or taken out of feathering configuration.

[0064] According to an advantageous variant, said main power supply device comprises: a main inverter device configured to be connected to the power supply and to deliver a main primary alternating voltage from the direct voltage delivered by said power supply, said main inverter device being fixed relative to the portion of the aircraft frame;and a main rotating transformer comprising a main primary circuit integral with the planet carrier of the reduction device and electrically connected to the main inverter device so that it receives the main primary alternating voltage, the main rotating transformer further comprising a main secondary circuit rotationally linked to said first rotating drive element and magnetically coupled to the main primary circuit so that it delivers a main secondary alternating voltage for the supply of the main electric motor.;

[0065] The main inverter device is located in the fixed frame. Insofar as the main primary circuit of the main rotating transformer is integral with the planet carrier of the reduction device, said main rotating transformer is described as "low radius." The main primary circuit of the main rotating transformer is advantageously fixed to the planet carrier. The control loop of the main electric motor is therefore located in the fixed frame. The main primary circuit is located in the fixed frame and belongs to a fixed part of the main power supply device, while the main secondary circuit is located in the first rotating frame and belongs to said rotating part of the power supply device.

[0066] Preferably, the main secondary circuit is connected, preferably directly, to the main stator of the main electric motor. Preferably, the main electric motor receives said main secondary alternating voltage.

[0067] The main rotating transformer is configured to transfer electrical power from the power supply to the main electric motor. The main rotating transformer can be single-phase or three-phase. Compared to a brushed commutator, the main rotating transformer has a smaller footprint and lighter weight. It is also less susceptible to wear, thus reducing maintenance requirements.

[0068] Preferably, the system further includes a capacitor connected to the power supply, the main inverter device, and the auxiliary inverter device, each having two input terminals between which the capacitor is connected. In other words, both the main inverter device and the auxiliary inverter device are connected to the capacitor. The capacitor presents the DC voltage supplied by the power supply across its terminals.

[0069] Advantageously, the main power supply device further includes a main regulator which is fixed relative to said portion of aircraft frame, said main regulator being configured to control said main inverter device in order to regulate the main primary AC voltage supplied by the latter to the main primary circuit of the main rotating transformer, from a main voltage setpoint.

[0070] It is understood that in this embodiment, the main inverter device is controllable. The main regulator is located in the fixed frame. The main regulator allows for indirect regulation, from the fixed frame, of the main secondary AC voltage supplied by the main rotating transformer that powers the main electric motor. The control loop of the main electric motor is located in the fixed frame. The main regulator advantageously allows for adjusting the frequency and amplitude of the main secondary AC voltage supplying the main electric motor. The main regulator advantageously allows for adjusting the rotational speed and direction of rotation of the main rotor of the main electric motor.

[0071] Preferably, the system includes a propeller blade orientation measuring device for the aircraft which is fixed relative to said portion of the aircraft frame, the computer being configured to generate said main voltage setpoint for said main regulator, from a measurement of the propeller blade orientation of the aircraft taken by means of said measuring device.

[0072] The measuring device advantageously comprises a plurality of sensors. The measuring device is positioned in a fixed reference frame, which improves the reliability of the measurements. The measuring device is configured to provide the propeller blade orientation measurement to the computer.

[0073] According to another advantageous variant, the system further comprises a second rotary drive element, integral with the planetary gear of said reduction device and configured to be driven in rotation by the aircraft turbomachine at a first rotational speed, the reduction device being configured such that the first rotary drive element is driven in rotation at a second rotational speed, lower than said first rotational speed, when the second rotary drive element is set in rotation at said first rotational speed, the main power supply comprising: a differential-speed main generator comprising a wound field winding carried by the second rotary drive element, so that it is configured to be driven in rotation at said first rotational speed, and an armature carried by the first rotary drive element,so that it is configured to be driven in rotation at said second rotational speed, the armature being configured to deliver a main alternating voltage for supplying the main electric motor; an excitation device configured to supply a direct current excitation voltage to the wound field winding of the main generator, the excitation device comprising an exciter machine including a field winding carried by the first rotary drive element and a wound armature carried by the second rotary drive element; and a secondary generator device for supplying the excitation device, configured to supply a direct current generator voltage to the field winding of the exciter machine of the excitation device,the secondary generator device comprising a permanent magnet generator including a permanent magnet inductor carried by the second rotating drive element and an armature carried by the first rotating drive element.

[0074] The assembly consisting of the main generator, the excitation device, and the secondary generator device forms a three-stage variable frequency generator (VFG). The main generator of the system according to the invention is said to be differential-speed, insofar as its wound field winding and its armature are both driven in rotation at different speeds. In other words, the wound field winding and the armature of the differential-speed main generator are positioned in two separate rotating frames.

[0075] Advantageously, the main power supply device further includes a control unit rotationally linked to the first rotary drive element, said control unit being configured to control said secondary generator device in order to regulate the DC generator voltage supplied by the latter to the inductor of the exciter machine, from a generator voltage setpoint.

[0076] The said control unit is located in the first rotating frame. The control unit indirectly regulates the main AC voltage supplied to the main electric motor by adjusting the DC generator voltage supplied by the secondary generator device.

[0077] Preferably, the system includes a computer fixed relative to the aircraft frame portion and configured to generate the generator voltage setpoint. Even more preferably, the system includes a signal transfer element configured to transfer the generator voltage setpoint from the computer to the secondary generator device. This signal transfer element is configured to transfer the setpoint from the fixed reference point to the first rotating reference point.Preferably, the permanent magnet generator is configured to deliver a first alternating voltage, the secondary generator device comprising: an AC-DC converter configured to deliver a first DC voltage from said first AC voltage; and a DC / DC converter configured to deliver said DC generator voltage from the first DC voltage delivered by the AC-DC converter.

[0078] Preferably, said control unit is configured to control said DC / DC converter in order to adjust the DC generator voltage it delivers.

[0079] Advantageously, the system includes a propeller blade orientation measuring device for the aircraft which is fixed relative to said portion of the aircraft frame, the computer being configured to generate said generator voltage setpoint, from a measurement of the propeller blade orientation of the aircraft taken by means of said measuring device.

[0080] 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.

[0081] Brief description of the drawings

[0082] 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:

[0083] [Fig. 1] Figure 1 illustrates a first embodiment of a pitch adjustment and de-icing system for the blades of an aircraft propeller according to the invention, given by way of example;

[0084] [Fig. 2] Figure 2 is a cross-sectional view of part of a turbomachine including the system of Figure 1, in the propeller area;

[0085] [Fig. 3] Figure 3 illustrates a second embodiment of a propeller pitch adjustment and de-icing system for an aircraft propeller according to the invention, given by way of example; and

[0086] [Fig. 4] Figure 4 illustrates a third embodiment of a pitch adjustment and de-icing system for the blades of an aircraft propeller according to the invention, given by way of example. 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 de-icing device, a main actuation device, and an auxiliary actuation device. The invention further relates to an aircraft comprising such a system.

[0087] Figure 1 shows a first embodiment, given by way of non-limiting example, of a system 10 for pitch adjustment and de-icing of the blades of an aircraft propeller, according to an example of the invention.

[0088] 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 shown in Figure 1. The turbomachine includes a propeller 12 comprising a plurality of blades 14. Only one of these blades 14 is shown in Figure 1.

[0089] The turbomachine 100 further comprises the propeller pitch adjustment and de-icing system 10. The system 10 includes, in particular, a main electric motor 40 used to drive a main actuation device 46 for adjusting the pitch of the propeller blades 14 of the propeller 12. The system further comprises an auxiliary electric motor 50 used to drive an auxiliary actuation device 56 for feathering and re-feathering the blades. The system also includes a propeller blade de-icing device 60. These elements will be described in detail later.

[0090] The system 10 further comprises a first rotary drive element 20, which is movable in rotation relative to the aircraft frame portion 102, about a principal axis X. The first rotary drive element 20 includes a drive shaft. The first rotary drive element 20 is configured to be driven in rotation by a low-pressure turbine of the turbomachine 100, via a reduction gear 24. The rotary drive element 20 defines a first rotating frame of reference.

[0091] 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 first 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 first rotary drive element 20, to 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 here has a reduction ratio of less than 1, approximately equal to 1 / 15.

[0092] The aircraft propeller 12 is rotationally linked to said first 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, in the area of ​​the propeller 12.

[0093] The main electric motor 40 is an asynchronous AC motor configured to be powered by an alternating voltage. It comprises a main stator 42 rotatably coupled to and carried by the first rotary drive element 20, such that it is configured to be driven in rotation by the first rotary drive element. The main stator 42 of the main electric motor 40 is arranged in the first rotating frame. The main stator 42 rotates about the main axis X. The main electric motor 40 further comprises a main rotor 44 coupled to the main stator 42 and driven in rotation about the main axis X when the main electric motor is energized. The main rotor 44 is arranged in a second rotating frame.

[0094] The main actuation device 46 is configured to adjust the orientation of the propeller blades 12. The main actuation device 46 can be electro-hydraulic or electromechanical. The main electric motor is configured to drive said main actuation device 46.

[0095] In this non-limiting example, the auxiliary electric motor 50 is a synchronous AC motor. It comprises an auxiliary stator 52 rotatably coupled to and carried by the first rotary drive element 20, such that it is configured to be driven in rotation by the first rotary drive element. The auxiliary stator 52 of the auxiliary motor 50 is located in the first rotating frame. The auxiliary stator 52 rotates about the main axis X. The auxiliary electric motor 50 further comprises an auxiliary rotor 54 coupled to the auxiliary stator 52 and driven in rotation about the main axis X when the auxiliary electric motor is activated. The auxiliary rotor 54 is located in a third rotating frame.

[0096] The auxiliary actuation device 56 is configured to adjust the orientation of the propeller blades 12 to bring them into or out of the feathered position. The auxiliary actuation device 56 is electro-hydraulic in type. It includes a bidirectional pump configured to drive an actuation cylinder. The bidirectional pump has a body rotatably linked to the aircraft propeller and is configured to supply hydraulic fluid to the actuation cylinder when actuated. The auxiliary electric motor 50 is configured to drive the auxiliary actuation device 56, and in particular the bidirectional pump.

[0097] Figure 1 shows that 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's 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 an auxiliary rectifier device 66, which here comprises a passive rectifier, i.e., a non-controllable rectifier. The control module further comprises a plurality of controllable mat switches 67 allowing selective control of the heating mats of the de-icing means 62.

[0098] 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 connected to the output of the power supply 22, such that it presents the DC voltage VDC across its terminals.

[0099] The system 10 also includes a main power supply 68 configured to supply electrical energy to the main electric motor 40. In this first, non-limiting embodiment, the main power supply 68 includes a main rotating transformer 70. The main rotating transformer 70 includes a main primary circuit 72 comprising at least one winding and a main secondary circuit 74 comprising at least one winding. As illustrated in Figures 1 and 2, the main primary circuit 72 is fixed relative to the aircraft frame portion 102 and is therefore located in the fixed frame. The main primary circuit 72 is integral with the planet carrier 28, such that the main rotating transformer 70 is said to be "low radius." More precisely, the main primary circuit 72 is supported by a fixed support 21, which is connected to the planet carrier 28 of the reduction gear 24.The main secondary circuit 74 is rotationally linked to the first rotating drive element 20 and is located in the first rotating frame. The main secondary circuit 74 is magnetically coupled to the main primary circuit 72. The main secondary circuit 74 is directly connected to the main stator 42 of the main electric motor 40.

[0100] The main power supply 68 also includes a main inverter 76 of the fixed duty cycle type. The main inverter 76 is electrically connected to the main primary circuit 72 of the main rotating transformer 70. The main inverter 76 is also connected to the power supply 22 so that it receives the said DC voltage VDC. More specifically, the main inverter 76 has two input terminals between which the said capacitor 23 is connected.

[0101] The main inverter device 76 is configured to deliver a main primary AC voltage VPACO to the main primary circuit 72 of the main rotating transformer 70 from the DC voltage VDC supplied by the power supply source 22.

[0102] The main rotating transformer 70 is configured to transfer electrical energy from the power supply 22, and therefore from the fixed reference frame, to the main electric motor 40, and thus to the first rotating reference frame. The main secondary circuit 74 of the main rotating transformer 70 is magnetically coupled to the main primary circuit 72, so that it delivers a main secondary AC voltage VSACO to the main stator 42 of the main electric motor 40, based on the main primary AC voltage VPACO received by the main primary circuit 72. The main secondary circuit 74 presents said main secondary AC voltage VSACO across its terminals.

[0103] The main stator 42, thus energized, drives the main rotor 44 of the main electric motor in rotation. The main rotor 44 of the main electric motor 40 drives the main actuation device 46. The latter is configured to convert the rotational motion of the main rotor 44 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 17.

[0104] The main power supply unit 68 also includes a main regulator 78 configured to control the main inverter unit 76 in order to regulate the primary main AC voltage VPACO delivered by the latter, based on a main voltage setpoint Co. The main regulator 78 thus indirectly regulates the secondary main AC voltage VSACO supplied by the main rotating transformer 70 to the main electric motor 40. The main regulator 78 is fixed relative to the aircraft frame portion 102, so that it is located in the fixed frame.

[0105] The system 10 further includes a measuring device 34 for the orientation of the propeller blades 14 of the aircraft. This measuring device 34 comprises a plurality of sensors associated with the propeller blades 14. The measuring device 34 is fixed relative to the aircraft frame portion 102, so that it is positioned in the fixed coordinate system. It is configured to provide a measurement m of the orientation of the propeller blades, considered along the longitudinal axis of said blades.

[0106] The system 10 also includes a computer 36 configured to generate said main voltage setpoint Co, from said measurement m of the orientation of the aircraft propeller blades provided by the measuring device 34. The computer 36 transmits this main voltage setpoint Co to the main regulator 78. The computer 36 is fixed relative to the portion of the aircraft frame 102, so that it is disposed in the fixed frame.

[0107] The system also includes an auxiliary rotating transformer 80. The auxiliary rotating transformer 80 comprises an auxiliary primary circuit 82 including at least one winding and an auxiliary secondary circuit 84 including at least one winding. As illustrated in Figures 1 and 2, the auxiliary primary circuit 82 is fixed relative to the aircraft frame portion 102 and is therefore located in the fixed frame. The auxiliary primary circuit 82 is integral with the planet carrier 28, so that the auxiliary rotating transformer 80 is said to be "low radius." More precisely, the auxiliary primary circuit 82 is integral with the fixed support 21, which is connected to the planet carrier 28 of the reduction gear 24. The auxiliary secondary circuit 84 is rotationally linked to the first rotary drive element 20 and is located in the first rotating frame. The auxiliary secondary circuit 84 is magnetically coupled to the auxiliary primary circuit 82.The auxiliary secondary circuit 84 is connected to the control module 64 of the defrosting device 60. Alternatively, the auxiliary secondary circuit 84 can be connected directly to the auxiliary electric motor.

[0108] The system 10 further includes an auxiliary inverter device 86 electrically connected to the auxiliary primary circuit 82 of the auxiliary rotating transformer 50. The auxiliary inverter device 86 is also connected to the power supply 22 so that it also receives the said DC voltage VDC. More specifically, the auxiliary inverter device 86 has two input terminals between which the said capacitor 23 is connected. The auxiliary inverter device 86 is arranged in the fixed position.

[0109] The auxiliary inverter device 86 is configured to provide an auxiliary primary AC voltage VPACI to the auxiliary primary circuit 82 of the auxiliary rotating transformer 80 from the constant DC voltage VDC supplied by the power supply source 22.

[0110] The auxiliary rotating transformer 80 is configured to transfer electrical energy from the power supply 22, and therefore from the fixed reference frame, to the defrosting device 60 and the auxiliary electric motor 50, and thus to the first rotating reference frame. The auxiliary secondary circuit 84 of the auxiliary rotating transformer 80 is magnetically coupled to the auxiliary primary circuit 82, so that it delivers an auxiliary secondary AC voltage VSACI to the control module 64 of the defrosting device 60, based on the auxiliary primary AC voltage VPACI received by the auxiliary primary circuit 82. The auxiliary secondary circuit 84 presents said auxiliary secondary AC voltage VsAci across its terminals.

[0111] The said secondary auxiliary alternating voltage VSACI is used to supply the defrosting unit 62 as well as the auxiliary electric motor 50. The auxiliary rotating transformer 80 is shared for the supply of electrical energy to the defrosting unit 62 and the auxiliary electric motor 50.

[0112] The system also includes an auxiliary regulator 88, which is fixed relative to the aircraft frame portion 102 and is therefore located in the fixed frame. This auxiliary regulator 88 is configured to indirectly regulate the auxiliary secondary AC voltage VSACI supplied by the auxiliary rotating transformer. To this end, the auxiliary regulator 88 is configured to control the auxiliary inverter device 86 in order to regulate the primary AC voltage VPACI supplied by the latter to the auxiliary primary circuit 82 of the auxiliary rotating transformer 80, based on an auxiliary voltage setpoint Ci.

[0113] This auxiliary voltage setpoint Ci is generated by the computer 36 from a measurement of the auxiliary primary AC voltage VPACI delivered by the auxiliary inverter device 86. This auxiliary voltage setpoint Ci is determined in order to regulate the auxiliary primary AC voltage VPACI, and indirectly the auxiliary secondary AC voltage VSACI, to a chosen value.

[0114] According to the invention, the defrosting means 62 and the auxiliary electric motor 50 are powered from the same auxiliary secondary alternating voltage, either directly or indirectly.

[0115] The system further includes a switching module 90 configured to selectively control the electrical power supply to the defrosting device 62 or, alternatively, to the auxiliary electric motor 50. In this non-limiting example, the control module 64 of the defrosting device 60 includes the switching module 90. In other words, the switching module allows for the exclusive control of either the power supply to the auxiliary electric motor 50 or the power supply to the defrosting device 62. The auxiliary electric motor 50 and the defrosting device 62 are not supplied with electrical power simultaneously.

[0116] In the first embodiment illustrated in the example of Figure 1, insofar as the auxiliary electric motor 50 is an asynchronous motor configured to be powered by an alternating voltage, said switching module 90 is connected on the one hand between the auxiliary secondary circuit 84 of the auxiliary rotating transformer 80 and the auxiliary electric motor 50, and on the other hand between said auxiliary secondary circuit 84 and the auxiliary rectifier device 66.

[0117] The switching module 90 is configured in a first configuration in which it controls the power supply to the defrosting unit 62, while the auxiliary electric motor 50 is not powered. The switching module 90 transmits the auxiliary secondary AC voltage VSACI to the auxiliary rectifier device 66. The auxiliary rectifier device 66 is then configured to supply the defrosting unit 62 with a DC voltage V afrom said auxiliary secondary alternating voltage VSACI which it receives, according to a defrosting setpoint C3. This defrosting setpoint C3 is generated and supplied to the control module 64 by the computer 36. The system further includes a signal transfer element 38 configured to transfer said defrosting setpoint C3 from the computer 36, located in the fixed frame, to the control module 64, located in the first rotating frame.

[0118] The switching module 90 is further configured to assume a second configuration in which it controls the power supply to the auxiliary electric motor 50, while the defrosting device 62 is not powered. In this non-limiting example, the switching module 90 directly transmits the aforementioned auxiliary secondary AC voltage VSACI to the auxiliary electric motor 50, so that the latter is directly powered by this auxiliary secondary AC voltage.

[0119] Figure 3 illustrates a second embodiment, given by way of non-limiting example, in which the auxiliary electric motor 50 is a DC motor configured to be powered by a DC voltage. In this non-limiting variant, the switching module 90 is connected on one side between the auxiliary rectifier device 66 and the conveyor belt switches 67 for controlling the conveyors of the defrosting unit 62, and on the other side between the rectifier device 66 and the auxiliary electric motor 50. In other words, the switching module 90 is connected to the output of the auxiliary rectifier device 66. In this non-limiting example, when the switching module 90 is in the first configuration, it controls the power supply to the defrosting unit 62 with a DC voltage V adelivered by the auxiliary rectifier device 66 from said auxiliary secondary AC voltage VSACI. When in the second configuration, the switching module 90 drives the auxiliary electric motor 50 with a DC voltage V m delivered by the auxiliary rectifier device 66 from said auxiliary secondary alternating voltage VSACI.. The switching module 90 then also includes a set of selectively actuable auxiliary switches allowing adjustment of the direction of the electric current supplied to the auxiliary electric motor 50 in order to adjust its direction of rotation.

[0120] In the examples in Figures 1 and 3, from the perspective of the first rotating frame, the power supply and control loop of the main electric motor 40 and the power supply and control loop of the defrosting device 62 and the auxiliary electric motor 50 are independent. These two control loops are further arranged in the fixed frame. The main rotating transformer 70 is dedicated to supplying the main electric motor 40, while the auxiliary rotating transformer 80 is dedicated to supplying the defrosting device 62 or the auxiliary electric motor 50, although these are not supplied simultaneously.

[0121] Figure 4 illustrates a third embodiment of a propeller pitch adjustment and de-icing system 10 for an aircraft propeller, given by way of non-limiting example. In this embodiment, the system includes a second rotary drive element 18 rotating at a first speed. The first rotary drive element 20 is driven at a second speed, lower than the first speed, via the reduction device 24. Furthermore, the auxiliary voltage setpoint Ci used by the auxiliary regulator 88 to control the auxiliary inverter device 86 is generated by the computer 36 from a measurement ai of the primary-secondary AC voltage VSACI delivered by the auxiliary rotating transformer 80.This measurement ai is transferred from the first rotating frame to the computer 36 located in the fixed frame via a signal transfer element 38.

[0122] Furthermore, in this third embodiment, the main power supply device 68' includes a secondary generator device 92. The latter comprises a permanent magnet generator 94 including a permanent magnet inductor 96 equipped with permanent magnets and an armature 98. The permanent magnet inductor 96 is carried by the second rotary drive element 18 and rotates at the first rotational speed. It is located in a fourth rotating frame. The armature 98 of the permanent magnet generator 92 is carried by the first rotary drive element 20 and rotates at the second rotational speed, in the first rotating frame. The armature 98 of the permanent magnet generator 94 delivers a first alternating voltage VIAC.

[0123] The secondary generator assembly 92 also includes an AC-DC converter 104 connected to the armature 98 of the permanent magnet generator 94. It forms a rectifier configured to deliver a first DC voltage Ve from the first AC voltage VIAC generated by the permanent magnet generator 94. The secondary generator assembly 92 further includes a controllable DC / DC converter 106 configured to convert the first DC voltage Ve delivered by the AC-DC converter 104 into a DC generator voltage Vgoc having a different amplitude than the DC voltage it receives. The AC-DC converter 104 and the DC / DC converter 106 are mounted on the first rotary drive element 20. They are positioned in the first rotating frame.

[0124] The main power supply 68' further includes an excitation device 108 connected in cascade with the secondary generator device 92. The excitation device 108 includes an exciter machine 110 connected to the DC / DC converter 106. The exciter machine comprises an inductor 112 and a wound armature 114. As illustrated in Figure 3, the inductor 112 is carried by, and fixed to, the first rotary drive element 20. The wound armature 114 of the exciter machine 110 is carried by the second rotary drive element 18. The DC generator voltage Vgoc delivered by the DC / DC converter 106 of the secondary generator device 92 is supplied to the inductor 112 of the exciter machine 110 for its power supply. The inductor 112 of the exciter machine then makes it possible to generate a magnetic field.Given this magnetic field and the relative movement between the inductor 112 and the armature 114 of the exciter machine, due to the difference in rotational speed between the latter, said wound armature 114 generates an alternating excitation voltage Ve. A c.

[0125] The excitation device 108 also includes a diode bridge 118 connected to the wound armature 114 of the exciter machine 110. It forms a rectifier configured to deliver a DC excitation voltage Veoc from the AC excitation voltage VCAC generated by the exciter machine. The diode bridge 118 of the excitation device 52 is supported by the second rotary drive element 18 and rotates at the first speed.

[0126] The main power supply unit 68' further comprises a differential-speed main generator 120, which includes a wound field winding 122 and an armature 124. The wound field winding 122 is connected to the excitation unit 108, specifically to the output of the diode bridge 118. The wound field winding 122 receives the DC excitation voltage Veoc, thus configuring it to generate a magnetic field. The wound field winding 122 is carried by the second rotary drive element 18. It also rotates at the first rotational speed of the second rotary drive element. The armature 124 is carried by the first rotary drive element 20. It is also configured to rotate at the second rotational speed.The difference between the second rotational speed of the first rotating drive element 20, and therefore of the armature 124 of the main generator 120, and the first rotational speed of the second rotating drive element 18, and therefore of the wound inductor 122 of the main generator, constitutes the differential speed.

[0127] Given the relative rotational motion of the wound inductor 122 with respect to the armature 124, caused by their difference in rotational speeds, and the magnetic field generated by the wound inductor, the armature of the main generator 120 delivers a main alternating voltage VITIAC which is directly supplied to the main electric motor 40 to power it. The assembly consisting of the secondary generator device 92, the excitation device 108, and the main generator 120 forms a three-stage variable frequency generator (VFG).

[0128] The main power supply unit 68' also includes a control unit 99, rotationally linked to the first rotary drive element 20 and configured to control the DC / DC converter 106 of the secondary generator unit 92 in order to regulate the DC generator voltage Vgoc supplied by the latter to the inductor 112 of the exciter machine 110, based on a generator voltage setpoint C2. This generator voltage setpoint C2 is provided by the computer 36 as a function of a measurement m of the propeller blade orientation. This generator setpoint C2 is transmitted from the computer located in the fixed frame to the control unit located in the first rotating frame via the signal transfer element 38.

Claims

Demands 1. A pitch adjustment and de-icing system (10) for the blades (14) of a propeller (12) of an aircraft, the aircraft comprising a power supply (22) delivering a direct current (DC) voltage and a frame portion (102) defining a fixed reference frame, the system comprising: at least one first rotary drive element (20) carrying the propeller; a reduction device (24) comprising: a planet gear (26) configured to be driven in rotation by a turbomachine of the aircraft; a ring gear (32) integral with the first rotary drive element (20); a planet carrier (28) fixed relative to said frame portion (102) of the aircraft; at least one planet gear (30) mounted pivotally relative to the planet carrier and cooperating with said planet gear and said ring gear so that said first rotary drive element is driven in rotation when the planet gear is driven in rotation;a main actuation device (46) configured to adjust the orientation of the propeller blades; a main electric motor (40) comprising a main stator (42) rotationally linked to said first rotating drive element and a main rotor (44) pivoting relative to the main stator and configured to drive the main actuation device; a main power supply device (68, 689) configured to supply the main electric motor with electrical power and comprising at least one rotating part rotationally linked to the first rotating drive element (20); an auxiliary actuation device (56) configured to selectively bring the propeller blades into a so-called feathered configuration in which they exhibit reduced drag, or into a so-called unfeathered configuration in which said blades extend transversely to a longitudinal direction of the aircraft;an auxiliary electric motor (50) having a stator; auxiliary (52) rotationally linked to the first rotary drive element and an auxiliary rotor (54) rotatable relative to the auxiliary stator and configured to drive the auxiliary actuation device to bring the propeller blades into the feathered or unfeathered configuration; a de-icing device (60) for said propeller blades carried by said first rotary drive element and comprising a de-icing means (62) including a set of heating mats, and a control module (64) configured to control said de-icing means, said control module including an auxiliary rectifier device (66) and a set of mat switches (67) allowing selective control of the heating mats;an auxiliary inverter device (86) configured to be connected to the power supply and to deliver an auxiliary primary alternating voltage (VPACI) from the direct voltage delivered by said power supply, said auxiliary inverter device being fixed relative to the portion of the aircraft frame; an auxiliary rotating transformer (80) comprising an auxiliary primary circuit (82) integral with the planet carrier of the reduction device and electrically connected to said auxiliary inverter device so that it receives said auxiliary primary alternating voltage, and an auxiliary secondary circuit (84) rotationally linked to said first rotating drive element and magnetically coupled to the auxiliary primary circuit so that it delivers an auxiliary secondary alternating voltage (VSACI) used to electrically supply the de-icing means and the auxiliary electric motor;and a switching module (90) configured to selectively control the electrical power supply: to said defrosting means with a DC voltage (V; a ) supplied by said auxiliary rectifier device (66) from said auxiliary secondary alternating voltage (ASAV); or from said auxiliary electric motor (50) with said auxiliary secondary alternating voltage or with a direct voltage (V m ) obtained from said auxiliary secondary alternating voltage (VSACI).

2. System according to claim 1, further comprising a computer (36) fixed relative to said portion of the aircraft frame (102), the computer being configured to generate one or more control setpoint(s) (Co,Ci,C2,C3) for the control of the auxiliary inverter device (86), the de-icing device (60) and / or the main power supply device (68).

3. A system according to claim 1 or 2, further comprising an auxiliary regulator (88) fixed relative to said portion of the aircraft frame (102), said auxiliary regulator being configured to control said auxiliary inverter device (86) in order to regulate the auxiliary primary AC voltage (VPACI) supplied by the latter to the auxiliary primary circuit (82) of the auxiliary rotating transformer (80), based on an auxiliary voltage setpoint (Ci), the computer (36) preferably being configured to generate said auxiliary voltage setpoint (Ci) for said auxiliary regulator (88), based on a measurement (ai) of the auxiliary primary AC voltage (VPACI) supplied to the auxiliary rotating transformer (80) or based on a measurement (az) of the auxiliary secondary AC voltage (VSACI) delivered by said auxiliary rotating transformer or based on a measurement of the DC voltage (V a) supplied by said auxiliary rectifier device (66) of the defrosting device control module (60).

4. System according to any one of claims 1 to 3, wherein the auxiliary electric motor (50) is an AC motor, for example an asynchronous motor, the switching module (90) being connected between the auxiliary electric motor and the auxiliary secondary circuit (84) of said auxiliary rotating transformer (80) so that said auxiliary electric motor is directly supplied by said auxiliary secondary AC voltage (ACV).

5. A system according to any one of claims 1 to 3, wherein said auxiliary electric motor (50) is a DC motor and wherein the switching module (90) is connected between said auxiliary rectifier device (66) and said auxiliary electric motor (50) so that it is configured to drive the power supply electric of the auxiliary electric motor with a direct voltage delivered by the auxiliary rectifier device from said auxiliary secondary alternating voltage (VSACI) supplied by the auxiliary secondary circuit (84) of the auxiliary rotating transformer (80).

6. System according to any one of claims 1 to 5, wherein said main power supply device (68) comprises: a main inverter device (76) configured to be connected to the power supply source (22) and to deliver a main primary alternating voltage (MPAV) from the direct current voltage (DCV) delivered by said power supply source, said main inverter device being fixed with respect to the frame portion (102) of the aircraft;and a main rotating transformer (70) comprising a main primary circuit (72) integral with the planet carrier of the reduction device and electrically connected to the main inverter device (76) so that it receives the main primary alternating voltage, the main rotating transformer further comprising a main secondary circuit (74) rotationally linked to said first rotary drive element (20) and magnetically coupled to the main primary circuit so that it delivers a main secondary alternating voltage (VSACO) for the supply of the main electric motor (40).

7. System according to claim 6, wherein the main power supply device (68) further comprises a main regulator (78) which is fixed with respect to said portion of the aircraft frame (102), said main regulator being configured to control said main inverter device (76) in order to regulate the main primary AC voltage (VPACO) supplied by the latter to the main primary circuit (72) of the main rotating transformer (70), from a main voltage setpoint (Co).

8. A system according to claims 2 and 7, wherein the system comprises a measuring element (34) for the orientation of the aircraft propeller blades, which is fixed relative to said portion of the aircraft frame (102), the computer (36) being configured to generate said main voltage setpoint (Co) for said main regulator (78), from a measurement (m) of the orientation of the aircraft propeller blades taken by means of said measuring device.

9. A system according to any one of claims 1 to 8, further comprising a second rotary drive element (18), integral with the planetary gear (26) of said reduction device (24) and configured to be driven in rotation by the aircraft turbomachine at a first rotational speed, the reduction device being configured such that the first rotary drive element (20) is driven in rotation at a second rotational speed, lower than said first rotational speed, when the second rotary drive element is set in rotation at said first rotational speed, the main power supply device (689) comprising: a differential-speed main generator (120) comprising a wound field winding (122) carried by the second rotary drive element, such that it is configured to be driven in rotation at said first rotational speed, and an armature (124) carried by the first rotary drive element,so that it is configured to be driven in rotation at said second rotational speed, the armature being configured to deliver a main alternating voltage (VrriAc) for the supply of the main electric motor (40); an excitation device (108) configured to supply a direct current excitation voltage (Veoc) to the wound field winding of the main generator, the excitation device comprising an exciter machine (110) comprising a field winding (112) carried by the first rotary drive element and a wound armature (114) carried by the second rotary drive element; and a secondary generator device (92) for supplying the excitation device, configured to supply a direct current generator voltage (Vgoc) to the field winding of the exciter machine of the excitation device,the secondary generator device comprising a permanent magnet generator (94) including a permanent magnet inductor (96) carried by the second rotating drive element and an armature (98) carried by the first rotating drive element.

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.

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