FR3145550A1 - Aircraft turbomachine propeller comprising an autonomous heating element supply system for defrosting and associated method - Google Patents

Abstract

An aircraft turbomachine propeller comprising a cone extending axially along an axis (X) and blades, the propeller being configured to be driven in rotation by a shaft of the turbomachine (A), the propeller comprising a plurality of heating members (2) and an electrical power supply system (3) for the heating members (2), the electrical power supply system (3) being mounted in the cone and configured to generate electrical energy autonomously from the rotation of the shaft of the turbomachine (A). Abstract figure: Figure 2

Description

Aircraft turbomachine propeller comprising an autonomous heating element supply system for defrosting and associated method

The present invention relates to the de-icing of a propeller of a turbomachine of an aircraft.

In a known manner, an aircraft comprises one or more turbomachines to enable propulsion. A turbomachine comprises at least one rotating shaft configured to drive a propeller in rotation, in particular, via a speed reducer known to those skilled in the art under the designation RGB for “Reduction Gear Box”. In a known manner, a propeller comprises an axially extending cone from which a plurality of radial blades extend.

During the flight of the aircraft, frost may form on the propeller blades. To remove it, it is known to equip the propeller blades with a plurality of heating members. In a known manner, a heating member is in the form of a heating mat comprising a plurality of resistors which are positioned on the leading edge of the blade but also on the cone. In the presence of icing conditions, the heating members are activated intermittently in order to separate the layers of frost. The layers of frost are then ejected due to the centrifugal force linked to the rotation of the propeller.

The heating elements are electrically powered and it is necessary to provide a significant electrical power in order to de-ice the propeller optimally. The electrical power is supplied to the de-icing system by an electrical source internal to the aircraft or the turbomachine. In practice, the electrical source is positioned in a fixed reference frame while the heating elements are positioned in a rotating reference frame linked to the blades. To allow the transfer of energy, it is necessary to provide a rotating transformer. The rotating transformer is connected to an electrical source via power harnesses. The installation of power harnesses from the electrical source to the transformer is complex and increases the mass and size of the turbomachine. This is particularly penalizing during maintenance operations. In addition, the routing of the power harnesses through several parts of the turbomachine is problematic since they require the creation of bending radii that are often unfeasible given the limited space requirement.

The invention aims to eliminate at least some of these drawbacks by proposing a heating element power supply system which is simple to install and maintain while having reduced mass and volume.

PRESENTATION OF THE INVENTION

The invention relates to an aircraft turbomachine propeller comprising a cone extending axially along an axis and blades, the propeller being configured to be driven in rotation by a shaft of the turbomachine, the propeller comprising a plurality of heating members and a system for electrically supplying the heating members.

The invention is remarkable in that the electrical power system is mounted in the cone and configured to generate electrical energy autonomously from the rotation of the turbomachine shaft.

Thanks to the invention, it is not necessary to provide a power harness, which limits the mass and size of the power supply system. In addition, since the electrical power supply system is autonomous, there is no need to carry out time-consuming connection steps with power harnesses. An electrical power supply system can be replaced in a practical manner. A mounting in the cone is advantageously accessible. Advantageously, this makes it possible to carry out de-icing without taking into account the main electrical sources of the aircraft, which has advantages for their dimensioning by limiting the integration constraints between the turbomachine and the aircraft.

Advantageously, the electrical energy is generated directly in a rotating reference point attached to the cone, which eliminates the need for a converter.

In one aspect, the power supply system includes a permanent magnet synchronous generator configured to generate electrical energy autonomously from the rotation of the turbomachine shaft. Such a generator makes it possible to generate an electric current making it possible to power the heating members.

According to one aspect, the permanent magnet synchronous generator comprises a first stator fulfilling an inductor function and a first rotor fulfilling an armature function, the first rotor being rotationally fixed to the shaft of the turbomachine. Thus, unlike a traditional permanent magnet synchronous generator, the first stator fulfills the inductor function and not the first rotor. This makes it possible to generate an electric current directly in the first rotor in order to power the heating members directly in the rotating reference frame. It is advantageous to do without a rotating transformer which requires an alternative electrical source and harnesses to route the electrical power supply to the transformer. Preferably, the first stator fulfills a magnet inductor function.

Preferably, the first rotor extends radially outwardly from the first stator. This makes it possible to supply the heating members located on the outer periphery of the propeller as closely as possible.

In one aspect, the armature is positioned radially outward and the inductor (magnets) is positioned radially inward.

In one aspect, the power supply system comprises a single electrical machine, in particular, only a permanent magnet synchronous generator.

According to one aspect, the electrical power supply system comprises an electrical power supply machine comprising a second stator fulfilling an inductor function and a second rotor fulfilling an armature function, the second rotor being rotationally fixed to the shaft of the turbomachine, the second stator being powered from the permanent magnet synchronous generator. Preferably, the second stator is wound.

A two-stage power supply system advantageously avoids the use of a rotating converter in the rotating reference frame. The power supply electric machine provides a power supply current directly to the heating elements. The power supply electric machine has a wound inductor and requires a power supply to become autonomous.

According to one aspect, the second rotor extends radially outwardly to the second stator. This makes it possible to naturally synchronize the supply of energy to the rotating reference and to supply as closely as possible the heating members located at the outer periphery of the propeller.

In one aspect, the second stator is powered by the first stator of the permanent magnet synchronous generator.

According to one aspect, the power supply system comprises a control computer configured to convert the supply current provided by the permanent magnet synchronous generator according to the supply current of the heating members. Preferably, the control computer directly supplies the second stator. In this case, the control computer preferably belongs to the fixed reference.

In one aspect, the power supply electrical machine is positioned downstream of the permanent magnet synchronous generator. This makes it possible to limit the overhang by positioning the heaviest equipment downstream.

In one aspect, the power supply system comprises an excitation electric machine comprising a third stator fulfilling an inductor function and a third rotor fulfilling an armature function, the third rotor being rotationally fixed to the shaft of the turbomachine, the third stator being powered by the permanent magnet synchronous generator, the first rotor powering the excitation electric machine which powers the supply electric machine so as to form a three-stage power supply system. In other words, the power supply system comprises three generators in cascade which share in common a fixed shaft and a rotating shaft.

In one aspect, the excitation electric machine is positioned upstream of the supply electric machine, preferably downstream of the permanent magnet synchronous generator. This makes it possible to limit the overhang by positioning the heaviest equipment downstream.

In one aspect, the third rotor extends radially outwardly of the third stator.

According to one aspect, the propeller comprising a fixed reference mark and a rotating reference mark integral in rotation with the cone, each rotor belongs to the rotating reference mark while each stator belongs to the fixed reference mark.

In one aspect, the power supply system includes a control computer configured to convert the power supply current provided by the permanent magnet synchronous generator based on the power supply current of the heating members.

In one aspect, the power supply system includes a defrost controller configured to provide the control computer with a power command, the control computer being configured to convert the supply current provided by the permanent magnet synchronous generator based on the supply current of the heaters and the power command.

In one aspect, the control computer is powered by the first rotor of the permanent magnet synchronous generator and the third rotor is powered by the control computer. In this case, the control computer preferably belongs to the rotating reference frame.

In one aspect, the power supply system comprises an electrical switch connected to a plurality of heating members. The power supply system thus ensures generation and distribution. A sequential control makes it possible to limit the size of the power supply system and allows it to be mounted in the cone. Preferably, the electrical switch is integral with the rotating marker.

Advantageously, the integration of an electrical switch in the power supply system makes it possible to aggregate all the functions linked to heating within a single piece of equipment, which facilitates both installation and maintenance.

In one aspect, the defrost controller is configured to provide the electrical switch with a sequence command to control sequential powering of the heaters.

In one aspect, the propeller comprises at least one speed reducer mounted between the shaft of the turbomachine and the cone. This advantageously allows the electrical power system to take advantage of the bearings of the speed reducer without integrating bearings specific to the electrical power system. This makes it possible to limit the air gap in the electrical machines and thus improves the reliability of the generation. It nevertheless goes without saying that the electrical power system could comprise its own bearings.

In one aspect, the heating members are resistive.

• Entrainer en rotation l’arbre de turbomachine pour entrainer en rotation les pales et
• Générer de l’énergie électrique à partir de la rotation l’arbre de turbomachine de manière à alimenter électriquement les organes de chauffage afin de dégivrer l’hélice. 

The invention further relates to a method of using a propeller as presented above, comprising steps consisting of:

• Rotate the turbomachine shaft to rotate the blades and
• Generate electrical energy from the rotation of the turbomachine shaft so as to electrically power the heating elements in order to defrost the propeller.

PRESENTATION OF FIGURES

The invention will be better understood upon reading the description which follows, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

There is a schematic representation of a propeller with an electrical power supply system for the heating members according to the invention.

There is a schematic representation of a first embodiment of an electrical power supply system.

There is a schematic representation of a second embodiment of an electrical power supply system.

There is a schematic representation of a third embodiment of an electrical power supply system.

It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be presented for an aircraft comprising a plurality of propeller turbomachines for providing propulsion of the aircraft, in particular, a plurality of turboprops.

In reference to the , there is schematically represented an aircraft turbomachine propeller 1. The propeller 1 comprises a cone 10, extending axially along an axis X, oriented from upstream to downstream on the , and blades 11 which extend, in this example, radially relative to the X axis.

The propeller 1 is configured to be driven in rotation by a shaft of the turbomachine A in order to rotate the blades 11 and generate propulsion work. Preferably, as illustrated in , the propeller 1 comprises a speed reducer RED mounted between the shaft of the turbomachine A and the cone 10 in order to modify the speed ratio. The propeller 1 comprises a fixed mark RF and a rotating mark RT integral in rotation with the cone 10.

The propeller 1 comprises a plurality of heating members 2 in order to allow the de-icing of the propeller 1. In a known manner, a heating member 2 is in the form of a heating mat comprising a plurality of resistors which are positioned on a leading edge of a blade 11 and on the cone 10. In the presence of icing conditions, the heating members 2 are activated intermittently in order to separate the layers of frost. The layers of frost are then ejected due to the centrifugal force linked to the rotation of the propeller 1. With reference to the , the propeller 1 comprises an electrical power supply system 3 for powering the heating elements 2.

According to the invention, the electrical power supply system 3 is mounted in the cone 10 of the propeller 1 and is autonomous. By autonomous, it is meant that the electrical power supply system 3 generates electrical energy only from the mechanical torque provided by the shaft of the turbomachine A without resorting to an external source as in the prior art. This advantageously makes it possible to do without power supply harnesses which increase the mass, size and complexity. The electrical power supply system 3 can be maintained and replaced in a practical and rapid manner.

According to one aspect of the invention, with reference to the , the electrical power supply system 3 comprises a permanent magnet synchronous generator 4 configured to generate electrical energy autonomously from the rotation of the shaft of the turbomachine A. The permanent magnet synchronous generator 4 comprises a first stator 41 fulfilling an inductor function and a first rotor 42 fulfilling an armature function, the first rotor 42 being integral in rotation with the shaft of the turbomachine A. This advantageously makes it possible to generate an electric current I4 at the first rotor 42 to power the heating members 2.

According to a first embodiment, with reference to the , the electrical power supply system 3 comprises an electrical switch 5 connected to a plurality of heating members 2. Advantageously, the electrical switch 5 makes it possible to control the sequential power supply of the heating members 2.

In this first embodiment, the electrical switch 5 is powered directly by the permanent magnet synchronous generator 4. Hereinafter, the current which powers the electrical switch 5 is referred to as “power supply current Ia”.

In this example, the electrical switch 5 is powered directly by the first rotor 42 of the permanent magnet synchronous generator 4 (Ia=I4). According to one aspect, the electrical power supply system 3 comprises a single electrical machine which is the permanent magnet synchronous generator 4.

Preferably, the electrical switch 5 further comprises an electrical converter 50, in particular an active (controlled) rectifier, in order to convert the supply current Ia into direct current. For the sake of clarity and conciseness, the electrical converter is not shown in all embodiments of the invention. It is shown in the to convert the current from the permanent magnet synchronous generator 4. As shown in , the electrical switch 5 is secured to the rotating reference RT to supply the heating elements 2. Depending on the architectures, it nevertheless goes without saying that an electrical converter is optional and that the electrical switch 5 could be supplied directly with alternating current. The electrical converter could also be passive (not controlled) and be in the form of a diode bridge, for example.

Still referring to the , the power supply system 3 further comprises a defrosting controller 6 configured to define the defrosting strategy, in particular, a power command C1 and a sequence command C2 which are sent to the electrical switch 5. In this example, the electrical switch 5 comprises a power converter 50 which receives the power command C1 to adjust the desired power.

The first rotor 42 of the permanent magnet synchronous generator 4 belongs to the rotating frame RT while the first stator 41 of the permanent magnet synchronous generator 4 belongs to the fixed frame RF. In this example, the first rotor 42 and the electrical switch 5 are connected to a rotating casing 12. The permanent magnet synchronous generator 4 is of the "inverted" type since the first rotor 42 extends radially outwardly to the first stator 41 relative to the X axis. As illustrated in FIG. , the permanent magnet synchronous generator 4 comprises a plurality of magnets 410 on the periphery of its first stator 41. Such an architecture makes it possible to naturally synchronize the supply of electrical energy with the rotating reference frame RT without adding an additional device such as a rotating transformer in the prior art.

Such a power supply system 3 is advantageous since it comprises little equipment and allows easy and practical maintenance. The power supply system 3 is advantageously autonomous. During the rotation of the turbomachine shaft A, the rotating casing 12 is also preferably driven via the reducer RED.

The rotation of the first rotor 42 of the permanent magnet synchronous generator 4 makes it possible to generate an induced current I4 by magnetic interaction with the magnets 410 of the first stator 41 which belongs to the fixed reference frame RF.

The induced current I4 corresponds to the supply current Ia of the electrical switch 5. The defrost controller 6 sends a power command C1 and a sequence command C2 to the electrical switch 5 which makes it possible to define the control strategy of the heating elements 2, i.e. the power and the defrosting time delay.

Thanks to the invention, it is not necessary to provide a passage for power supply harnesses. The electrical power supply system 3 is autonomous and independent. This makes it possible to make the de-icing devices independent of the aircraft generation and distribution system, which avoids oversizing and limits constraints.

In this first embodiment, the permanent magnet synchronous generator 4 is associated with a power converter 50 controlled in the rotating reference frame RT to manage the power level to be supplied to the heating elements 2. This affects the reliability and availability of the electrical power supply system 3. In this embodiment, the permanent magnet synchronous generator 4 must remain permanently active even in non-icing conditions, which increases the fire risk and limits its lifespan.

A second embodiment is shown in . For the sake of clarity and conciseness, elements identical or similar to the first embodiment are not described again.

According to the second embodiment, with reference to the , the electrical power supply system 3 further comprises an electrical power supply machine 7 comprising a second stator 71 fulfilling an inductor function and a second rotor 72 fulfilling an armature function. The second rotor 72 is rotationally integral with the shaft of the turbomachine A. The second stator 71 is powered by the permanent magnet synchronous generator 4, in particular, via the first stator 41.

A two-stage architecture advantageously makes it possible to reduce the size of the permanent magnet synchronous generator 4, in particular, by eliminating the power converter 50 presented in FIG. , which allows an overall reduction in the mass and size of the power supply system 3.

In order to control the power supply power, the power supply system 3 further comprises a control computer 8. As illustrated in , the second stator 71 is supplied indirectly by the permanent magnet synchronous generator 4 via the control computer 8.

As illustrated in the , the permanent magnet synchronous generator 4 generates an alternating current I4 in the first stator 41 which is transformed by the control computer 8 into a direct current I8 to supply the second stator 71 and generate an alternating current I7 in the second rotor 72 to supply the electrical switch 5 (Ia=I7).

Since the first stator 41 and the second stator 71 belong to the fixed frame RF, it is advantageous to place the control computer 8 in the fixed frame RF as illustrated in . In this example, the control computer 8 comprises an electrical converter of the rectifier type. Optionally, with reference to the , the control computer 8 can also supply direct or alternating current to other auxiliary electrical loads AUX.

The control computer 8 is configured to receive the power command C1 from the defrost controller 6 so as to precisely determine the current I8 to be supplied to the second stator 71.

According to one aspect, as illustrated in , the control computer 8 is connected to a current sensor 80 configured to measure the current I7 supplied by the second rotor 72 of the electrical supply machine 7. This advantageously allows the control computer 8 to determine the current I8 to be supplied to the second stator 71 by control from the power command C1 and the supply current Ia (current I7 supplied by the second rotor 72).

Since the second rotor 72 belongs to the rotating reference frame RT and the control computer 8 belongs to the fixed reference frame RF, it is preferable to use a contactless inductive sensor 80. It goes without saying that the control computer 8 could measure any physical quantity (current or voltage) which is the image of the current I7.

In this second embodiment, the permanent magnet synchronous generator 4 and the control computer 8 are sized to directly supply the excitation power to the electrical supply machine 7, i.e. approximately 1/ ^10th of the power of the heating members 2.

A third embodiment is shown in . For the sake of clarity and conciseness, elements identical or similar to the second embodiment are not described again.

According to the third embodiment, with reference to the , the electrical power supply system 3 further comprises an electrical excitation machine 9 comprising a third stator 91 fulfilling an armature function and a third rotor 92 fulfilling an inductor function. The third rotor 92 is rotationally integral with the shaft of the turbomachine A.

The third rotor 92 is powered by the permanent magnet synchronous generator 4, in particular, via the first rotor 42. Such a power supply is convenient since they all belong to the rotating frame RT.

In this example, the third rotor 92 of the excitation electric machine 9 is supplied indirectly by the first rotor 42 of the permanent magnet synchronous generator 4 via the control computer 8. As illustrated in , the permanent magnet synchronous generator 4 generates an alternating current I4 in the first rotor 42 which is transformed by the control computer 8 into direct current I8 to supply the third rotor 92.

The second stator 71 of the supply electric machine 7 is supplied by the third stator 91 of the excitation electric machine 9 as illustrated in . Preferably, the third stator 91 of the excitation electric machine 9 generates an alternating current which is rectified via a rectifier 93 to supply the second stator 71 of the supply electric machine 7 with a direct current I9. In this example, the rectifier 93 is in the form of a diode bridge. The supply electric machine 7 generates an alternating current I7 in the second rotor 72 in order to supply the electric switch 5 (Ia=I7).

A three-stage architecture advantageously makes it possible to reduce the overall mass and size of the electrical power supply system 3. With this architecture, the permanent magnet synchronous generator 4 and the electrical excitation machine 9 are small in size compared to the second embodiment of the (approximately 1/ ^100th of the power of the heating elements 2).

In the first embodiment, the permanent magnet synchronous generator 4 is the main (and only) equipment that supplies electrical power to the heating members 2. In the second embodiment, the permanent magnet synchronous generator 4 is a secondary source of excitation of the power supply electric machine 7. The permanent magnet synchronous generator 4 supplies approximately 10% of the electrical power to the heating members 2. In the third embodiment, the permanent magnet synchronous generator 4 is also a secondary source of excitation of the power supply electric machine 7. The permanent magnet synchronous generator 4 supplies approximately 1% of the electrical power to the heating members 2.

Since the first rotor 42 and the third rotor 92 belong to the rotating frame RT, it is advantageous to place the control computer 8 in the rotating frame RT as illustrated in .

Similarly to previously, the control computer 8 is configured to receive the power command C1 from the defrosting controller 6 so as to precisely determine the current I8 to be supplied to the third rotor 92.

According to one aspect, as illustrated in , the control computer 8 is connected to a current sensor 81 configured to measure the current I7 (mI7) supplied by the second rotor 72 of the supply electrical machine 7. This advantageously allows the control computer 8 to determine the current I8 to be supplied to the third rotor 92 by servocontrol from the power command C1 and the measurement mI7 of the supply current Ia (current I7 supplied by the second rotor 72). Given that the third rotor 92 belongs to the rotating reference frame RT and that the control computer 8 belongs to the rotating reference frame RT, a traditional current sensor 81 can advantageously be used.

A three-stage 3-phase power supply system allows for simple and easy-to-maintain integration while saving weight and mass.

In order to enable optimum cooling of the power supply system 3, several cooling devices may advantageously be provided. For example, a fan may be mounted in the cone 10 to cool the electrical equipment 4, 7, 9. Similarly, the rotating casing 12 may be equipped with cooling fins. Advantageously, the speed reducer comprises a cooling circuit, for example an oil circuit, which supplies a cooling circuit of the power supply system in a synergistic manner.

Claims (12)

Propeller (1) of an aircraft turbomachine comprising a cone (10) extending axially along an axis (X) and blades (11), the propeller (1) being configured to be driven in rotation by a shaft of the turbomachine (A), the propeller comprising a plurality of heating members (2) and an electrical power supply system (3) for the heating members (2), the electrical power supply system (3) being mounted in the cone (10) and configured to generate electrical energy autonomously from the rotation of the shaft of the turbomachine (A). Propeller (1) according to claim 1 in which the electrical power supply system (3) comprises a permanent magnet synchronous generator (4) configured to generate electrical energy autonomously from the rotation of the shaft of the turbomachine (A). Propeller (1) according to claim 2 in which the permanent magnet synchronous generator (4) comprises a first stator (41) fulfilling an inductor function and a first rotor (42) fulfilling an armature function, the first rotor (42) being integral in rotation with the shaft of the turbomachine (A). Propeller (1) according to claim 3 in which the first rotor (42) extends radially outwardly to the first stator (41). Propeller (1) according to one of claims 3 to 4 in which the electrical power supply system (3) comprises an electrical power supply machine (7) comprising a second stator (71) fulfilling an inductor function and a second rotor (72) fulfilling an armature function, the second rotor (72) being integral in rotation with the shaft of the turbomachine (A), the second stator (71) being powered from a permanent magnet synchronous generator (4). Propeller (1) according to claim 5 in which the second rotor (72) extends radially outwardly to the second stator (71). Propeller (1) according to one of claims 5 to 6, in which the electrical power supply system (3) comprises an electrical excitation machine (9) comprising a third stator (91) fulfilling an inductor function and a third rotor (92) fulfilling an armature function, the third rotor (92) being rotationally fixed to the shaft of the turbomachine (A), the third stator (91) being powered by the permanent magnet synchronous generator (4), the first rotor (42) powering the electrical excitation machine (9) which powers the electrical power supply machine (7) so as to form a three-stage electrical power supply system (3). Propeller (1) according to one of claims 1 to 7, comprising a fixed reference (RF) and a rotating reference (RT) integral in rotation with the cone (10), each rotor (42, 72, 92) belongs to the rotating reference (RT) while each stator (41, 71, 91) belongs to the fixed reference (RF). Propeller (1) according to one of claims 1 to 8, in which the electrical power supply system (3) comprises a control computer (8) configured to convert the supply current supplied by the permanent magnet synchronous generator (4) as a function of the supply current of the heating members (2). Propeller (1) according to claim 9, in which the electrical power supply system (3) comprises a defrosting controller (6) configured to provide the control computer (8) with a power command (C1), the control computer (8) being configured to convert the supply current provided by the permanent magnet synchronous generator (4) as a function of the supply current of the heating members (2) and of the power command (C1). Propeller (1) according to one of claims 1 to 10, in which the electrical power supply system (3) comprises an electrical switch (5) connected to a plurality of heating members (2). Method of using a propeller (1) according to one of claims 1 to 11, comprising steps consisting of:

• Rotate the turbomachine shaft (A) to rotate the blades (11) and
• Generate electrical energy from the rotation of the turbomachine shaft (A) so as to electrically power the heating elements (2) in order to defrost the propeller (1).