Turbine propeller including high power de-icing system

Abstract

An aircraft turbine propeller comprising a propeller fairing and a blade, the propeller fairing and the blade comprising a plurality of heating components (220) and a system (222) for supplying power to the plurality of heating components, the invention relates to a power supply system (290) mounted in a propeller fairing and configured to autonomously generate electrical energy by rotation of a turbine main shaft (216) driving the propeller in rotation, said power supply system comprising a motor (290) having: a rotating stator (230B) acting as an armature and fixed synchronously in rotation to the main shaft of the turbine; and a rotor (230A) which functions as an excitation inductor and is fixed to a high-speed auxiliary shaft (232) in a synchronous rotation manner, the rotation speed of the high-speed auxiliary shaft being greater than the rotation speed of the main shaft of the turbine.

Description

Technical Field

[0001] This invention relates to the field of electric (electrothermal) de-icing of propeller fairings and blades for aircraft turbines. Background Technology

[0002] Climate change is a major concern for many legislative and regulatory bodies worldwide. In fact, various limits on carbon emissions have been, are being, or will be adopted by countries. In particular, a high standard applies to both new and existing aircraft, requiring the implementation of technological solutions to ensure compliance with current regulations. Civil aviation has been actively contributing to addressing climate change for many years.

[0003] Technological research has resulted in significant improvements to the environmental performance of aircraft. The applicant considers influencing factors at all design and development stages to obtain more energy-efficient and environmentally friendly aviation components and products, whose integration and use in civil aviation have a moderate environmental impact, aiming to improve the energy efficiency of aircraft.

[0004] Therefore, the applicant continuously strives to reduce climate impact and minimize greenhouse gas emissions as much as possible by using sound development and manufacturing methods and processes, thereby reducing the environmental footprint of the activities.

[0005] These ongoing research and development efforts focus on next-generation aircraft turbines, aircraft weight reduction (particularly through the use of materials and lighter onboard equipment), technological advancements that utilize electrical technologies to ensure propulsion, and aviation biofuels as an important complement to technological progress.

[0006] However, in electric or hybrid-electric aircraft, as well as conventional aircraft, several surfaces on the stationary and rotating parts of the turbine must be protected from icing when the turbine operates under icing conditions (high altitude, clouds, fog). Ice buildup can indeed impair the dynamic performance of propeller blades by creating imbalances and deteriorating airfoils. Protective measures envisioned to address this buildup typically employ electrothermal methods, based on heating pads formed by resistive grids covering the surfaces to be protected, installed in different areas of the turbine. These resistors are interconnected over long distances by electrical and signal harnesses that traverse various areas of the turbine. These harnesses also require specific protection, particularly shielding, to protect them from external hazards and also from electromagnetic interference to surrounding systems. This significantly increases their size, making wiring and integration within the height-constrained space of the turbine extremely difficult, and sometimes impossible.

[0007] Furthermore, to ensure power transmission and transfer electrical energy from the stationary section to the rotating section equipped with heating pads, a device called a "slip ring" is known. This works by rubbing several fixed conductive rings, fixed to the stationary section, against a circular conductive track, fixed to the rotating section, thereby establishing an electrical connection between the stationary and rotating parts of the turbine. However, the main drawback of this solution is its very limited lifespan due to wear and tear on components caused by continuous friction. This results in unacceptable operating costs on single-aisle commercial aircraft such as the A320 or B737, where the rotating section undergoes significant rotation.

[0008] Therefore, there is still a need today for a power generation solution that is synchronized with the rotating reference frame of the propeller blades, which would allow the elimination of the power harness requirements between the fixed and rotating reference frames of the turbine, and would be particularly suitable for situations where the power required for de-icing is very high.

[0009] The invention application described herein advantageously proposes a solution for reducing mass, which provides enhanced gains by improving the fuel consumption of the turbine. Summary of the Invention

[0010] Therefore, this invention is the result of technical research aimed at significantly improving aircraft performance and, in this respect, helping to reduce the environmental impact of these aircraft.

[0011] Therefore, the primary objective of this invention is to generate electrical energy directly in a rotating reference frame from the mechanical power extracted from the rotating parts of the turbine, without the need for additional transmission mechanisms. Another objective is to allow the extracted power level to be controlled according to the needs of a computer monitoring the turbine de-icing system. Yet another objective is to provide a compact system that facilitates installation in the nose cone fairing and propeller maintenance operations.

[0012] These objectives are achieved by an aircraft turbine propeller comprising a propeller fairing and blades, the propeller fairing and blades including multiple heating elements and a system for supplying power to the multiple heating elements, the system being mounted in the propeller fairing and configured to autonomously generate electrical energy by the rotation of the turbine's main shaft that drives the propeller to rotate, the power supply system including a motor comprising: a rotating stator acting as an armature and synchronously rotatably fixed to the turbine's main shaft; and a rotor acting as an excitation inductor and synchronously rotatably fixed to a high-speed auxiliary shaft, the high-speed auxiliary shaft rotating at a speed greater than that of the turbine's main shaft.

[0013] The resulting autonomous power supply is optimized in terms of quality and size, and can be easily integrated into the turbine's nose cone (rotating part) even in harsh environments, eliminating the limitation of wiring harnesses passing through multiple modules of the turbine.

[0014] The main shaft of the turbine and its driving propeller is located outside the propeller according to the invention. The propeller of the invention is adapted to be coupled to this shaft; in other words, the propeller is configured to rotate and drive together with the main shaft of the turbine.

[0015] Preferably, the rotation of the high-speed auxiliary shaft is achieved by a speed increaser installed between the main shaft and the fixed shaft. This speed increaser can be a reverse rotation speed increaser.

[0016] According to the envisioned embodiment, the motor is a three-stage synchronous generator, including a synchronous motor, a main exciter, and an auxiliary exciter associated with a generator control unit; or another three-stage synchronous generator, including two cascaded generators and an exciter associated with a generator control unit. The auxiliary exciter and the exciter preferably include an excitation inductor in the form of a permanent magnet rotor.

[0017] In the first embodiment, the armature of the main exciter and the excitation sensor of the auxiliary exciter are fixed to the high-speed auxiliary shaft, and the excitation sensor of the main exciter, the armature of the auxiliary exciter, and the generator control unit are fixed to the main shaft or to a fixed shaft.

[0018] In the second embodiment, the excitation inductor of the first generator is multiphase and is directly powered by the multiphase armature of the second generator. The phase sequence of the multiphase armature of the second generator is crossed, such that the rotation direction of the rotating magnetic field of the multiphase excitation inductor of the first generator is opposite to the rotation direction of the rotating magnetic field of the multiphase armature of the second generator.

[0019] Preferably, in order to provide current or voltage measurements to the generator control unit, a non-contact rotation sensor is installed between the fixed shaft and the main shaft when the generator control unit is fixed to the fixed shaft.

[0020] Advantageously, the speed increaser is integrated into the motor or into the gearbox of the turbine.

[0021] The present invention also relates to an aircraft turbine including the aforementioned propeller. Attached Figure Description

[0022] Other features and advantages of the invention will become apparent from the following description with reference to the accompanying drawings, which illustrate an exemplary embodiment and are not limiting, wherein:

[0023] Figure 1 This is a schematic diagram of the front part of a propeller-driven aircraft turbine according to the present invention;

[0024] Figure 2A This demonstrates ensuring that the speed increaser is located inside the motor. Figure 1 A first exemplary embodiment of the power supply system for the heating component of the propeller de-icing device;

[0025] Figure 2B This illustrates the case where the speed increaser is located outside the motor. Figure 2A A first exemplary embodiment;

[0026] Figure 3 It shows the assurance Figure 1 A second exemplary embodiment of the power supply system for the heating component of the propeller de-icing device; and

[0027] Figure 4 It shows the assurance Figure 1 A third exemplary embodiment of the power supply system for the heating component of the propeller de-icing. Detailed Implementation

[0028] The basic principle of this invention is based on the use of an electric motor, the armature of which (considered as the stator of the motor) rotates in the same reference frame as the load to be powered, while the excitation inductor (considered as the rotor of the motor) which rotates in the same way is fixed on a high-speed auxiliary shaft. When the excitation inductor is fixed in the fixed reference frame of the turbine, the speed difference of the high-speed auxiliary shaft is greater than the speed difference between the armature and the excitation inductor.

[0029] Therefore, the differential speed at the air gap between the motor's armature and excitation inductor can be increased. This differential speed is the sum of the speed of the low-speed shaft (carrying the load) and the speed of the high-speed auxiliary shaft (considering the direction of rotation, i.e., whether the shafts are rotating in opposite directions). This allows for a solution with reduced mass and size, because, under the same power and constant thermal conditions, the mass and size of the motor are directly related to the differential speed observed at the air gap between the rotor and stator.

[0030] The high-speed auxiliary shaft can rotate in the opposite direction to achieve a greater speed difference (a low-speed shaft at 1,000 rpm provides a 19,000 rpm difference with a high-speed shaft at 20,000 rpm, while using a high-speed shaft rotating in the opposite direction at the same speed results in a 21,000 rpm difference). In this configuration, the armature and excitation inductor rotate in opposite directions relative to a common fixed reference frame (RF). The armature is fixed to and therefore synchronized with the rotating part of the turbine that drives the propeller blades, and is thus referred to as the low-speed reference frame (RL) in the reference frame of the load to be powered. By introducing a counter-rotating speed increaser between the shaft of the armature corresponding to the low-speed reference frame and the shaft of the excitation inductor corresponding to the high-speed and counter-rotating reference frame (RR), the excitation inductor is driven at a higher speed in the opposite direction to the armature.

[0031] Figure 1 An aircraft turbine propeller is schematically shown. The propeller 10 includes: a propeller fairing 12 extending axially along the longitudinal XX-axis of the turbine; and blades 14 extending substantially radially relative to the XX-axis. The propeller is configured to be driven to rotate by the turbine's main shaft 16, causing the blades to rotate and generate propulsive work. Typically, the propeller includes a reduction gearbox (RGB) 18 mounted between the turbine's main shaft and the propeller fairing to change the speed ratio. For de-icing, the propeller includes multiple heating elements 20, known to take the form of heating pads comprising: multiple resistors positioned on the leading edge of the blades 14 and the outer surface of the propeller fairing 12. Under icing conditions, the heating elements 20 are intermittently activated to separate ice layers, which are then flung out by centrifugal force associated with the propeller's rotation. The propeller 10 includes a power supply system 22 to power the heating elements 20 for this de-icing process.

[0032] According to the present invention, the power supply system 22 is installed in the propeller fairing 12 of the propeller and is an autonomous electrical system independent of the aircraft. Autonomous means that the power supply system 22 generates electrical energy solely from the mechanical torque provided by the turbine's main shaft 16, unlike prior art systems which rely on external sources. This advantageously eliminates the need for power harnesses that increase the mass, size, and complexity of the power supply system, thus allowing for convenient and quick maintenance and replacement.

[0033] Figure 2A and Figure 2B A first exemplary embodiment of a system for powering a heating element 220 to ensure de-icing of a turbine propeller is shown. The power supply system 222 includes a motor 290 comprising: a rotating stator 230B acting as an armature and rotatably fixed to the turbine's main shaft 216; and a rotor 230A acting as an excitation inductor and rotatably fixed to a high-speed auxiliary shaft 232, which rotates at a higher speed and in the opposite direction to the turbine's main shaft 216 (counter-rotating rotor) due to the introduction of a counter-rotating speed increaser 234. The speed increaser 234 may be located inside the motor 290, such as... Figure 2A As shown, or located outside the motor 290, such as Figure 2B As shown. Regardless of whether the speed increaser 234 is located inside or outside the motor 290, it is mounted between the main shaft 216 and the fixed shaft 238, ensuring the rotation of the high-speed auxiliary shaft 232. Figure 2B In this configuration, when the speed increaser 234 is located outside the motor 290, the three shafts have interfaces (connections) between the motor 230 and the reduction gearbox, but... Figure 2AIn this configuration, when the speed increaser 234 is located inside the motor 290, the two shafts have an interface. The high-speed auxiliary shaft 232 (which can rotate in the opposite direction when the high-speed auxiliary shaft is rotated in the opposite direction) allows for an increase in the differential speed between the armature and the excitation inductor of the motor 290, thereby reducing its mass and size.

[0034] Coupled to the 290 motor upstream of the reduction gearbox (RGB), this allows for an optimized solution (the motor has its own bearings, allowing for a small air gap of approximately 1 mm to less than 2 mm, while eliminating radial and axial displacement) and shared cooling resources (especially the bearing oil already present at the RGB), while facilitating its integration at the head fairing (in an area accessible for maintenance). It also allows for a reduction in the number of power electronics components on the rotating parts.

[0035] In the configuration shown in Figure 2, the motor 290 coupled to the reverse rotation speed increaser 234 is a synchronous generator referred to as a three-stage synchronous generator, which consists of the following parts: the synchronous motor 230 itself, which includes an inner wound excitation inductor 230A fixed to a high-speed auxiliary shaft 232 forming a high-speed reference frame RR and an outer wound armature 230B fixed to a main shaft 216 forming a low-speed reference frame RL and synchronized with the rotating reference frame of the propeller blades; and a main exciter 236, which includes a fixed excitation inductor 236A fixed to a fixed shaft 238 and a high-speed auxiliary shaft 216 fixed to a fixed shaft 238 forming a high-speed reference frame RR. The armature 236B on the 32 exciter supplies power to the excitation inductor 230A of the synchronous motor via a rotating diode bridge 240 and is fixed on the high-speed auxiliary shaft 232; and the auxiliary exciter 242 includes an excitation inductor 242A and a fixed armature 242B. The excitation inductor 242A is in the form of a permanent magnet rotor 244 fixed on the high-speed auxiliary shaft 232, and the fixed armature 242B is fixed on the fixed shaft 238 and supplies AC power to the generator control unit (GCU) 246 fixed on the fixed shaft 238, which improves its reliability and the overall quality of the configuration.

[0036] The operation of motor 290 is ensured by generator control unit 246, which converts the alternating current received from auxiliary exciter 242 into direct current to provide continuous excitation to the stationary portion of main exciter 236 according to the current to be supplied to heating pad 220 or any other load mounted in a fixed reference frame. Generator control unit 246 receives current (or voltage) measurements from the load via non-contact rotation sensor 248 mounted between main shaft 216 and stationary shaft 238.

[0037] The reverse rotation speed increaser 234, which is inserted between the main shaft 216 and the fixed shaft 238 and ensures the rotation of the high-speed auxiliary shaft 232, has a speed increase ratio that can be selected by those skilled in the art based on criteria for reducing mass, size and reliability.

[0038] Figure 3 A second exemplary embodiment of a system 322 for powering the heating element 320 is shown, which differs from the previous embodiment in that the excitation sensor 336B of the main exciter 336, the armature 342A of the auxiliary exciter 342, and the generator control unit 346 are all fixed to the main shaft 316, rather than to the fixed shaft 338, and therefore they are located in the low-speed rotating reference frame RL of the load. However, the diode bridge 340 remains fixed to the high-speed auxiliary shaft 332 and is therefore rotating. An advantage over the previous configuration is that the generator control unit 346 receives current (or voltage) measurements from the load via a direct sensor (not shown) because it is located in the same reference frame as the load.

[0039] In this second exemplary embodiment, the speed increaser 334 is located inside the motor 390. As in the first exemplary embodiment ( Figure 2B In this configuration, the speed increaser 334 can also be located outside the motor 390.

[0040] In these two exemplary embodiments, note that there are dimensional differences (albeit illustrative) between the main exciter 336 and the auxiliary exciter 342 and the main synchronous motor 390. Typically, the power-to-size ratio between the main motor and the main exciter is approximately 10, while the ratio between the main motor and the auxiliary exciter is approximately 1 / 100.

[0041] Figure 4 A third exemplary embodiment is shown, which eliminates the need for rotation. Figure 2A , Figure 2B and Figure 3 The diode bridges 240 and 340 require, and the motor 490 coupled to the reverse rotation speed increaser 434 is also a synchronous generator referred to as a three-stage synchronous generator, but this generator includes two cascaded generators 450 and 452. More specifically, it consists of: a first generator 450, which includes a multiphase excitation inductor 450A fixed to a reverse rotation high-speed auxiliary shaft 432 forming a high-speed reference frame RR and a rotating armature 450B fixed to a main shaft 416 forming a low-speed reference frame RL and synchronized with a rotating reference frame of the propeller blades; and a second generator 452, which includes a fixed DC excitation inductor 452A and a multiphase armature 452B fixed to the high-speed auxiliary shaft 432. The armature 452B of the second generator 452 directly supplies power to the excitation inductor 450A of the first generator 450 according to the known cascading principle. The exciter 442 includes: an excitation inductor 442A in the form of a permanent magnet rotor 444, which is fixed on the high-speed auxiliary shaft 432; and a fixed armature 442B, which provides alternating current to the generator control unit 446, which is also fixed on the fixed shaft 438 located in the fixed reference frame RF.

[0042] Two phases of the three phases of the armature 452B of the second generator 452 (in the case of a three-phase generator) are crossed, such that the rotation direction of the rotating magnetic field of the excitation inductor 450A of the first generator 450 is opposite to the rotation direction of the rotating magnetic field of the armature 452B. Therefore, as is known, the mechanical speed (reverse rotation) of the support shaft and the electrical speed of the rotating magnetic field of the excitation inductor of the main motor are added together.

[0043] In this third exemplary embodiment, the speed increaser 434 is located inside the motor 490. As in the first exemplary embodiment ( Figure 2B The speed increaser 434 can also be located outside the motor 490.

[0044] Therefore, to ensure anti-icing protection for aircraft turbine propellers, this invention provides an autonomous, optimized, and compact power generation solution that powers the propeller fairing and blade heating pads based on the principle of a high-speed auxiliary shaft, and allows the following objectives to be achieved compared to existing technologies:

[0045] - Synchronizes the power supply with the propeller's rotating reference frame without requiring additional transmission mechanisms.

[0046] - By integrating the power supply system into the propeller fairing, maintenance and operation are simplified.

[0047] - In an advantageous configuration, the generator control unit (GCU) is mounted on a fixed part to improve its reliability.

Claims

1. An aircraft turbine propeller (10), comprising: The propeller fairing (12) and blades (14) include a plurality of heating elements (20, 220, 320, 420) and a system (22, 222, 322, 422) for supplying power to the plurality of heating elements. The system for supplying power to the plurality of heating elements is mounted in the propeller fairing and is configured to autonomously generate electricity by the rotation of the main shaft (16, 216, 316, 416) of the turbine that drives the propeller to rotate. Yes, the power supply system includes motors (290, 390, 490), each motor comprising: a rotating stator (230B, 330B, 450B) which acts as an armature and is synchronously rotated and fixed to the main shaft of the turbine; and a rotor (230A, 330A, 450A) which acts as an excitation inductor and is synchronously rotated and fixed to a high-speed auxiliary shaft (232, 332, 432), the high-speed auxiliary shaft rotating at a speed greater than that of the main shaft of the turbine.

2. The aircraft turbine propeller according to claim 1, wherein, The rotation of the high-speed auxiliary shaft (232, 332, 432) is achieved by speed increasers (234, 334, 434) installed between the main shaft (216, 316, 416) and the fixed shaft (238, 338, 438).

3. The aircraft turbine propeller according to claim 1 or 2, wherein, The motors (290, 390) are three-stage synchronous generators, including synchronous motors (230, 330), a main exciter (236, 336) and an auxiliary exciter (242, 342), the auxiliary exciter being associated with the generator control unit (246, 346).

4. The aircraft turbine propeller according to claim 3, wherein, The armature (336A) of the main exciter and the excitation sensor (342B) of the auxiliary exciter are fixed to the high-speed auxiliary shaft (332), and the excitation sensor (336B) of the main exciter, the armature (342A) of the auxiliary exciter and the generator control unit (346) are fixed to the main shaft (316).

5. The aircraft turbine propeller according to claim 3, wherein, The armature (236B) of the main exciter and the excitation sensor (242A) of the auxiliary exciter are fixed to the high-speed auxiliary shaft (232), and the excitation sensor (236A) of the main exciter, the armature (242B) of the auxiliary exciter and the generator control unit (246) are fixed to the fixed shaft (238).

6. The aircraft turbine propeller according to claim 1 or 2, wherein, The motor (490) is a three-stage synchronous generator, comprising two cascaded generators (450, 452) and an exciter (442) associated with the generator control unit (446).

7. The aircraft turbine propeller according to claim 6, wherein, The excitation inductor (450A) of the first generator (450) is multiphase and is directly powered by the multiphase armature (452B) of the second generator (452). The phase sequence of the multiphase armature of the second generator is crossed, such that the rotation direction of the rotating magnetic field of the multiphase excitation inductor (450A) of the first generator is opposite to the rotation direction of the rotating magnetic field of the multiphase armature (452B) of the second generator.

8. The aircraft turbine propeller according to claim 3 or 6, wherein, The auxiliary exciter (242, 342) and the exciter (442) include excitation inductors (242A, 342A, 442A) in the form of permanent magnet rotors.

9. The aircraft turbine propeller according to claim 3 or 6 further includes a non-contact rotation sensor (248, 348, 448) mounted between the fixed shaft (238, 338, 438) and the main shaft (216, 316, 416) to provide current or voltage measurements to the generator control unit.

10. The aircraft turbine propeller according to any one of claims 1 to 9, wherein, The speed increaser is a reverse rotation speed increaser (234, 334, 434).

11. An aircraft turbine, comprising: The propeller according to any one of claims 1 to 10.

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