INTEGRATED UNIT FOR TRANSFERRING ROTATIONAL ENERGY FROM AN ELECTRIC CHAIN ​​FOR DE-Icing PROPELLER BLADES AND THE NOSE CONE OF A TURBOMACH

Description

Technical Field

[0001] The present invention relates to the general field of de-icing of propeller blades and the front cone of a turbomachine, and more particularly to the electric de-icing chain and the transfer of power between the fixed part and the rotating part of the turbomachine. Previous technique

[0002] Turbomachinery, from the upstream end, comprises one or more compressor modules arranged in series, which compress air drawn in through an air intake. The air is then introduced into a combustion chamber where it is mixed with fuel and burned. The combustion gases pass through one or more turbine modules that drive the compressor(s). The gases are then ejected either through a nozzle to produce propulsion or onto a free turbine to generate power, which is then transmitted to a drive shaft.

[0003] Modern high-bypass turbofan engines consist of a fan rotor and several compressor stages, including a low-pressure compressor and a high-pressure compressor, both part of the engine's primary core. Upstream of the low-pressure compressor is a large, rotating impeller, or fan, which supplies both a primary airflow through the low-pressure and high-pressure compressors and a secondary airflow, or cold airflow, directed to a cold air nozzle, known as the secondary nozzle. The fan is driven by the low-pressure core's rotor shaft.

[0004] The protection against icing of the fan blades and the leading edge of a turbomachine is based on electrothermal de-icing. Heating mats, consisting of a network of resistors, are integrated into the leading edges of the blades and the leading edge. In icing conditions, a layer of ice is intentionally allowed to form on the leading edges. The heating mats are then energized for a specific duration to heat the surface of the blades and the leading edge, thus loosening the ice layers. As the blades and leading edge rotate, these ice layers are ejected by centrifugal force.

[0005] The surfaces of the turbomachine that need de-icing are large and therefore require a significant amount of electrical power to supply the heating mats, with the power dedicated to de-icing coming from the aircraft's generators. figure 1 Figure 120 represents an electrical circuit of a prior art de-icing system connected to the heating mats' resistors 110 and to the power supplies 131, 132 and the turbomachine's control system 130. The electrical circuit 120 includes DC-to-AC voltage converters 123 that supply AC voltage to rotating transformers 122. To limit the power supplied to the de-icing system and other non-propulsive systems, the resistors 110 of one pair of propeller blades are energized for only a specified time, then the resistors of the next pair are energized, and so on, each pair consisting of one blade and its opposite, all connected in series with a sector of the front cone. The alternating supply of the resistors 110 of the pairs of blades is achieved by means of the switches 121 placed between the resistors 110 and the rotating transformers 122.

[0006] To operate the electrical circuit 120 of the de-icing system, certain connections are required, such as those for the low-voltage DC power supply 142, the high-voltage DC power supply 141, and the communication links 143 between the components 121, 122, and 123 of the electrical circuit 120 and the control system 130 of the turbomachine. This necessitates routing numerous harnesses 141, 142, and 143 within the turbomachine while adhering to specific installation constraints, such as restrictions on harness bend radii or the spacing between harnesses and / or between turbomachine components. These constraints result in an increase in the mass and volume of the turbomachine, as well as complex installation and maintenance of the de-icing system.

[0007] Documents US2013307378 A1, US2011290942 A1 and US2015108760 A1 describe electrical defrosting systems known in the prior art.

[0008] It is therefore desirable to have an electrical defrosting system that meets installation constraints while reducing the mass, volume and integration complexity of the defrosting system. Description of the invention

[0009] The invention relates to an integrated rotating power transfer unit for an electrical circuit for de-icing propeller blades and the front cone of a turbomachine, comprising: a rotating transformer comprising a static part and a rotating part; a DC-to-AC voltage converter connected at its output to the static part of the rotating transformer and intended to be connected at its input to a DC power supply; and a power switch connected to the rotating transformer and configured to transmit electrical power to at least one pair of propeller blades and the front cone of the turbomachine.

[0010] The invention thus makes it possible to combine the rotating transformer, the switch, and the converter within a single piece of equipment to form an integrated rotating power transfer unit. In other words, they are located locally in the same place within the turbomachine. The integrated unit is therefore more compact and can be installed in the turbomachine in a small diameter area, thereby limiting the highly stressful and damaging centrifugal acceleration forces on the electronic components.

[0011] Integrating all components into a single unit reduces, or even eliminates, the need for numerous long cables and harnesses between de-icing system components, as well as reducing the number and size of electromagnetic interference (EMI) filters. This allows for a reduction in the mass and volume of the electrical de-icing system.

[0012] Furthermore, thanks to the integrated unit, resources such as cooling and low-voltage power supply can be shared between these three components. This also allows for flexibility in connector orientation (axial or circulation orientation, for example) to facilitate the routing of power harnesses from the unit to the blade roots or the nose cone.

[0013] Finally, the integrated unit offers flexibility in the choice of design and arrangement of components within the unit to, for example, facilitate maintenance, improve cooling efficiency or interconnections between components.

[0014] According to a particular feature of the invention, the integrated unit comprises a first electrical path including the rotating transformer, the converter and the switch, and a second path including a second rotating transformer comprising a static part and a rotating part, a second DC voltage to AC voltage converter and a second power switch, the second converter being connected at its output to the static part of the second rotating transformer and intended to be connected to a DC power supply and the second switch being connected to the second rotating transformer and configured to transmit electrical power to at least one pair of propeller blades and to the front cone of the turbomachine.

[0015] Having two redundant electrical circuits ensures that the de-icing system is always functional even if one of the circuits fails.

[0016] According to another particular feature of the invention, the integrated unit comprises at least one DC-to-DC voltage converter associated with the DC-to-AC voltage converter and connected to the DC power supply of the associated DC-to-AC voltage converter and configured to generate a low-voltage power supply.

[0017] The presence of a DC-to-DC converter allows for the generation of a local low-level voltage (for example, a 28V DC voltage), i.e., within the integrated unit. This allows, for each electrical channel, the integrated unit to be connected to a single external high-voltage power supply and reduces the number of cables between the unit and its environment.

[0018] According to another particular feature of the invention, the integrated unit comprises a plurality of rotating transformers in each electrical track, and within each electrical track, each rotating transformer is associated with a separate pair of propeller blades, the DC-to-AC voltage converter is common to the rotating transformers of the electrical track, and the switch comprises switches configured to select one of the rotating transformers of the electrical track.

[0019] Thanks to this feature, each rotary transformer is only powered during the activation time of its corresponding propeller blade pair. This allows the switch electronics to be inserted between the DC / AC converter and the rotary transformers, positioning the switch on the static part of the integrated unit and thus eliminating centrifugal stress on the electronics.

[0020] According to another particular feature of the invention, in each electrical path, the rotating transformer and the power switch are combined.

[0021] This allows for a single rotary transformer in each electrical channel capable of powering all pairs of propeller blades, with the rotary transformer having at least as many outputs as there are pairs of blades. Furthermore, the switch electronics can also be located on the stationary part of the rotary transformer.

[0022] Another object of the invention is a turbomachine comprising an integrated power transfer unit rotating according to the invention and a low pressure speed reducer, the integrated unit being integral with the low pressure speed reducer.

[0023] The low pressure speed reducer, also called in English Reduction Gear Box, RGB, is interposed between the blower which includes the propeller blades and the low pressure shaft of the turbomachine.

[0024] It drives the turbine's fan blades, resulting in a lower blade rotation speed than the low-pressure shaft. This speed reduction allows for an increase in the fan size.

[0025] Having the integrated unit attached to the low-pressure speed reducer allows for a defrosting system close to the speed reducer and offers a more compact, more efficient, lighter and easier maintenance system, because it is more accessible.

[0026] According to a particular feature of the invention, the low pressure speed reducer comprises a rotating part and a fixed shaft, the rotating part of the rotating transformers of the integrated unit is integral with the rotating part of the low pressure speed reducer, and the static part of the rotating transformers, the power switches and the DC to AC voltage converters of the integrated unit are integral with the fixed shaft of the low pressure speed reducer.

[0027] According to another particular feature of the invention, the low pressure speed reducer comprises a rotating part and a fixed shaft, the rotating part of the rotating transformers and the power switches of the integrated unit are fixed to the rotating part of the low pressure speed reducer and the static part of the rotating transformers and the DC to AC voltage converters of the integrated unit are fixed to the fixed shaft of the low pressure speed reducer.

[0028] These two assembly variants of the unit integrated with the fixed (fixed shaft) and rotating parts of the low-pressure speed reducer eliminate the need for bearings on the integrated unit, thus improving its reliability and lifespan. They also eliminate the effects of imbalance and displacement due to proximity to the speed reducer bearings, reduce mechanical clearance between the fixed and rotating parts of the integrated unit for weight savings, particularly in the rotating transformer, increase the size and efficiency of the entire electrical de-icing system, and finally, provide accessible and replaceable equipment under the wing without special tools, facilitating maintenance, assembly, and disassembly.

[0029] According to another particular feature of the invention, the turbomachine includes blades present on an external surface of the integrated unit and attached to the rotating part of the low pressure speed reducer.

[0030] The fins create a forced airflow around the integrated unit, allowing the components of the integrated unit assembled on the rotating part of the speed reducer to cool.

[0031] According to another particular feature of the invention, the turbomachine includes a blower attached to the rotating part of the low pressure speed reducer.

[0032] The blower blows air to cool the components of the integrated unit assembled on the rotating part of the speed reducer. Components assembled on the stationary part can also benefit from this airflow for cooling. The blower can be advantageously combined with cooling fins to further improve the cooling of the integrated unit. Brief description of the drawings

[0033] Other features and advantages of the present invention will become apparent from the description given below, with reference to the attached drawings which illustrate examples of embodiment without any limiting character. [ Fig. 1 ] There figure 1 represents, schematically and partially, a defrosting system according to the prior art. Fig. 2 ] There figure 2 represents, schematically and partially, an integrated unit of a defrosting system according to an embodiment of the invention. Fig. 3 ] There figure 3 represents, schematically and partially, the assembly of the rotating parts of the unit integrated into a low-pressure speed reducer according to an embodiment of the invention. Fig. 4 ] There figure 4 represents, schematically and partially, the assembly of the rotating parts of the unit integrated into a low-pressure speed reducer according to another embodiment of the invention. Fig. 5 ] There figure 5 represents, schematically and partially, an integrated unit and its assembly to a low pressure speed reducer according to another embodiment of the invention. Description of the implementation methods

[0034] There figure 2 This schematically and partially represents an integrated rotating power transfer unit 220 of a de-icing system according to an embodiment of the invention. Throughout the description, a pair of propeller blades is formed by a blade 1101 and its opposite 1102. The blade and its opposite are connected to a sector 1121, 1122 of the front cone 110 of the turbomachine. Furthermore, the blades 1101, 1102, the sectors 1121, 1122, and the front cone 110 include heating mats composed of a network of resistors 1111, 1112, 1113, 1114, 1115, 1116 for de-icing. Although not shown in the figures, the propeller blades and the front cone can also be connected to each other in parallel.

[0035] The integrated unit 220 of the defrosting system's electrical circuit comprises two redundant electrical paths. The first electrical path includes a rotary transformer 2221 connected to a DC-to-AC converter 2231 (or DC / AC converter 2231) at its input and to a power switch 2211 at its output. The second electrical path also includes a rotary transformer 2222 connected to a DC-to-AC converter 2232 (or DC / AC converter 2232) at its input and to a power switch 2212 at its output. Each rotary transformer 2221 and 2222 comprises a stationary section and a rotating section. These two rotary transformers 2221 and 2222 can be completely independent, or each can have a winding around the same magnetic circuit.The power switches 2211, 2212 of both channels are connected to at least one pair of propeller blades 1101, 1102 and to the front spinner 110 of the turbomachine. In this figure, for clarity, only one pair of blades is shown; however, the switches 2211, 2212 of both channels can be connected to all pairs of propeller blades of the turbomachine. The DC / AC converters 2231, 2232 are each connected at their input to a high-voltage DC power supply 2321, 2322 and at their output to the static part of the rotating transformer associated with their respective power channel. In order to generate a low-voltage power supply, the integrated unit 220 also includes, in each power channel, a DC-to-DC converter 2241, 2242 (or DC / DC converter).The first channel's DC / DC converter 2241 is connected at its input to the high-voltage DC power supply 2321 and generates a low voltage in the first channel; while the DC / AC converter 2242 is connected at its input to the high-voltage DC power supply 2322 and generates a low voltage in the second electrical channel. Both DC / DC converters 2241 and 2242 generally provide the low-voltage power supply for the turbomachine's control electronics.

[0036] The integrated unit 220 is also connected to the turbomachine control system 230. Therefore, the only utilities connected to the integrated unit 220 are the high-voltage power supply 2411, 2412 and the communication 2431, 2432. However, an additional utility connection between the low-voltage power supply 2311, 2312 and the integrated unit 220 is possible if the unit 220 does not include DC / DC converters.

[0037] There figure 3 represents schematically and partially, the assembly of the rotating parts 3201, 3202 of the integrated unit 320 to a low pressure speed reducer 330 according to an embodiment of the invention.

[0038] The components of the integrated unit 320 are placed in a cylindrical housing closed by flanges 321 and 322. The housing and its flanges 321 and 322 are assembled to the speed reducer 330. Thus, the integrated unit 320 is integral with the speed reducer 330, in particular its rotating parts 3201, 3202 are integral with the rotating parts of the speed reducer 330. The flanges 321 and 322 are fixed to the speed reducer 330 using, for example, sets 370 of screws and nuts. The flanges 321 include ventilation grilles 361, 362 to allow hot air to be evacuated from the integrated unit 320, the ventilation grilles 362 of the flange 322 being opposite the ventilation grilles 360 of the speed reducer 330.More specifically, the ventilation grille 361 of the flange 321 allows cold air to enter the integrated unit 320, while the ventilation grilles 360 of the speed reducer 330 and 362 of the flange 322 allow hot air to be expelled from the integrated unit 320. In this embodiment, the sets 370 of screws and nuts for assembling the integrated unit 320 to the speed reducer 330 are located inside the integrated unit 320.

[0039] The speed reducer 330 includes a fixed shaft 331 through which the utilities 3411, 3412, 3431, 3432 are routed to the integrated unit 320.

[0040] There figure 4 represents schematically and partially, the assembly of the rotating parts 4201, 4202 of the integrated unit 420 to a low pressure speed reducer 430 according to another embodiment of the invention.

[0041] The components of the integrated unit 420 are placed in a cylindrical housing closed by two flanges 421 and 422. The housing is assembled to the speed reducer 430 via its flanges 421 and 422. Thus, the integrated unit 420 is integral with the speed reducer 430, in particular its rotating parts 4201, 4202 are integral with the rotating parts of the speed reducer 430. The flanges 421 and 422 are fixed to the speed reducer 430 using, for example, sets 470 of screws and nuts. The flange 421 includes a ventilation grille 461 to allow hot air to be exhausted from the integrated unit 420. More specifically, the ventilation grille 461 allows cold air to be drawn into the integrated unit 420. The speed reducer 430 also includes ventilation grilles 460 to exhaust hot air from the integrated unit 420.In this embodiment, the sets 470 of screws and nuts for assembling the integrated unit 420 to the speed reducer 430 are placed outside the integrated unit 420.

[0042] As before, the speed reducer 430 includes a fixed shaft 431 through which the utilities 4411, 4412, 4431, 4432 are routed to the integrated unit 420.

[0043] There figure 5 represents schematically and partially, the assembly of the integrated unit 520 to a low pressure speed reducer 530 according to an embodiment of the invention.

[0044] The fixed parts 5203 and 5204 of the integrated unit 520 are fixed to the fixed shaft 531 of the low-pressure speed reducer 530. Specifically, the integrated unit 520 includes a hollow, sliding shaft 571 that is rotationally immobilized. This immobilization is achieved, for example, by a key. The hollow shaft 571 allows the various auxiliary components of the integrated unit 520 to be routed via the fixed shaft 531 of the speed reducer 530, such as the electrical power supplies 5411 and 5412 and the communication connections 5431 and 5432 with the turbomachine control system. The translational immobilization of the hollow shaft 571 is achieved, for example, by a slotted nut 570 mounted at the end of the shaft 571.

[0045] The rotating and fixed parts of figures 3 , 4 And 5 include rotating transformers, DC / AC converters, DC / DC converters and power switches of the two electrical paths described in figure 2 The stationary section comprises the static portion of the rotating transformers, the DC / DC converters, and the DC / AC converters, while the rotating section comprises the rotating portion of the rotating transformers. Power switches can be located in either the stationary or rotating section. If the switches are in the stationary section of the integrated unit, they are typically positioned between the DC / AC converters and the stationary portion of the rotating transformers; whereas if they are in the rotating section of the integrated unit, they are typically positioned between the rotating portion of the rotating transformers and the resistors of the propeller blade pairs and the front cone of the turbomachine. Placing the switches in the rotating section of the integrated unit frees up space for the DC / AC converters and / or brings the outputs of the integrated unit closer to the resistors of the propeller blade pairs and the front cone.

[0046] The placement of DC / AC converters, DC / DC converters, power switches, and rotating transformers within the integrated unit is tailored to meet reliability and / or cooling requirements. For example, to improve cooling, temperature-sensitive components can be placed in contact with the external surfaces of the integrated unit's housing and close to the cold air intake grille. Similarly, to minimize mechanical stress from centrifugal forces, certain components of the rotating part of the integrated unit can be positioned as close as possible to the axis of rotation.

[0047] In addition, the integrated unit 320, 420, 520 may include one or more blowers 341, 342, 441, 442, 541, 542 attached to the rotating part 3201, 3202, 4201, 4202, 5201, 5202 of the integrated unit 320, 420, 520. These blowers 341, 342, 441, 442, 541, 542 blow forced air to remove heat from the integrated unit 320, 420, 520.

[0048] Fins 551, 552 can also be mounted on an external, rotating surface of the integrated unit 520 (as shown in figure 5 ) to accelerate the surrounding air and create a forced airflow which also allows heat to be removed from the integrated unit 520, in particular from the rotating elements 5201, 5202 of the integrated unit 520.

[0049] It is also possible to place fins 561, 562 inside the integrated unit 520, so that these fins 561, 562 are fixed to the fixed parts 5203, 5204 of the integrated unit 520. These three cooling solutions can be implemented alone or in combination on the integrated unit 520, in order to adapt to different constraints: cooling, size, mass, etc.

[0050] Furthermore, advantageously, the elements placed in the rotating parts of the integrated unit presented in figures 3 , 4 And 5 are assembled and distributed symmetrically around the speed reducer to ensure the balance of the assembly and avoid creating imbalances.

[0051] The integrated unit may also have its own bearings, particularly on the flange side, if integration or other constraints require it.

[0052] Regardless of the embodiment of the invention, the integrated unit comprises a plurality of rotary transformers, each transformer being associated with a distinct pair of propeller blades. If, for example, there are N pairs of propeller blades (N being greater than or equal to 1), there will be N rotary transformers in each electrical channel of the integrated unit. Within an electrical channel, each rotary transformer is powered only during the activation time of the corresponding pair of blades. To power the rotary transformers of the same channel, the integrated unit may include a single DC / AC converter per channel (and optionally also a single DC / DC converter), and the power switch includes switches for activating the rotary transformer associated with the active pair of blades.

[0053] Within the same electrical track, it is also possible to combine the rotary transformer and the power switch. In this configuration, the rotary transformer has as many outputs as there are pairs of propeller blades to power, and the switch combined with the rotary transformer acts as a selector to choose the rotary transformer output corresponding to the active pair of propeller blades. More specifically, an electromagnetic actuator is associated with a single primary circuit of the rotary transformer, and the selector is controlled to position the actuator—and therefore the primary circuit of the rotary transformer—with the secondary circuit of the rotary transformer corresponding to the active pair of blades for the duration of that pair's de-icing cycle. There is always only one DC / AC converter per track.

[0054] Regardless of the implementation method, the DC / AC converter can be single-phase, three-phase or have another topology.

[0055] Regardless of the embodiment, the rotating transformer can be single-phase, three-phase or have another topology.

[0056] Regardless of the embodiment, the switch can be direct current or alternating current.

Claims

1. An integrated unit (220, 320, 420, 520) for transferring rotary power from an electrical circuit for de-icing the propeller blades (1101, 1102) and the nose (110) of a turbomachine comprising: - a rotary transformer (2221) comprising a static part and a rotary part; - a DC-to-AC voltage converter (2231) connected at its output to the static part of the rotary transformer and intended to be connected at its input to a DC electrical power supply (2321), and - a power switch (2211) connected to the rotary transformer and configured to transmit electrical power to at least one pair (1101, 1102) of propeller blades and to the nose cone (110) of the turbomachine, characterized in that it comprises a DC-to-DC voltage converter (2241, 2242) connected at its input to the DC electrical power supply (2321, 2322) of the DC-to-AC voltage converter (2231, 2232) and configured to generate a low-voltage electrical power supply.

2. The integrated unit as claimed in claim 1, comprising a first electrical channel comprising the rotary transformer (2221), the converter (2231) and the switch (2211), and a second channel comprising a second rotary transformer (2222) comprising a static part and a rotary part, a second DC-to-AC voltage converter (2232) and a second power switch (2212), the second converter being connected at its output to the static part of the second rotary transformer and intended to be connected at its input to a DC electrical power supply (2322) and the second switch being connected to the second rotary transformer and configured to transmit electrical power to at least one pair of propeller blades (1101, 1102) and to the nose cone (110) of the turbomachine.

3. The integrated unit as claimed in claim 2, wherein each electrical channel comprises a DC-to-DC voltage converter (2241, 2242) connected at its input to the DC electrical power supply of the DC-to-AC voltage converter (2231, 2232) of the electrical channel and configured to generate a low-voltage electrical power supply.

4. The integrated unit as claimed in any of claims 2 or 3, comprising a plurality of rotary transformers in each electrical channel, and within each electrical channel, each rotary transformer is associated with a separate pair of propeller blades; the DC-to-AC voltage converter is common to the rotary transformers of the electrical channel and the switch comprises switches configured to select one of the rotary transformers of the electrical channel.

5. The integrated unit as claimed in any of claims 2 or 3, wherein, in each electrical channel, the rotary transformer and the power switch are combined.

6. A turbomachine comprising an integrated unit (320, 420, 520) for transferring rotary power as claimed in any of claims 1 to 5 and a low-pressure reduction gear (330, 430, 530), the integrated unit being secured to the low-pressure reduction gear.

7. The turbomachine as claimed in claim 6, wherein the low-pressure reduction gear comprises a rotary part and a fixed shaft (331, 431, 531), the rotary part of each of the rotary transformers of the integrated unit is secured to the rotary part of the low-pressure reduction gear, and the static part of the rotary transformer or transformers, the power switch or switches and the DC-to-AC voltage converter or converters of the integrated unit are secured to the fixed shaft of the low-pressure reduction gear.

8. The turbomachine as claimed in claim 6, wherein the low-pressure reduction gear comprises a rotary part and a fixed shaft, the rotary part of the rotary transformer or transformers and the power switch or switches of the integrated unit are secured to the rotary part of the low-pressure reduction gear and the static part of each of the rotary transformers and the DC-to-AC voltage converter or converters of the integrated unit are secured to the fixed shaft of the low-pressure reduction gear.

9. The turbomachine as claimed in any of claims 6 to 8, comprising des fins (551, 552) located on an outer surface of the integrated unit (520) and secured to the rotary part of the low-pressure reduction gear.

10. The turbomachine as claimed in any of claims 6 to 9, comprising a fan (341, 342, 441, 442, 541, 542) secured to the rotary part of the low-pressure reduction gear (330, 430, 530).