Aircraft braked wheel

Abstract

Aircraft wheel (1) comprising a rim (2) equipped with rotor discs (11b) driven in rotation with the rim by means of first studs (7) integral with the rim and engaged in notches in the rotor discs, stator discs (11a) being interposed between the rotor discs and provided with notches engaged on second studs (15) integral with a torsion tube (12) of a brake fixed in rotation relative to an axle (4) carrying the wheel, characterized in that the wheel comprises at least one heat exchanger (20, 21) arranged to capture the heat transmitted by the discs to at least one of the first or second studs, and at least one power supply unit (30) configured to electrically supply an electrical system equipping the wheel,the power supply unit comprising at least one thermoelectric module (31) a first face of which is in contact with the heat exchanger to transform the heat captured by said heat exchanger into an electric current. FIGURE IN ABRIDGED DIAGRAM: Fig. 3,

Description

Title of the invention: Aircraft braked wheel

[0001] The present invention relates to the field of aeronautics and more particularly to the power supply of electrical systems equipping aircraft braked wheels.

[0002] BACKGROUND OF THE INVENTION

[0003] An aircraft landing gear generally comprises a leg having a first end connected to an aircraft structure and a second end provided with an axle on which a wheel is mounted for pivoting. The wheel includes a rim connected by a flange to a hub that receives the axle and, together with the rim, defines a space in which a stack of brake discs is arranged. The stack of discs comprises alternating stator discs rotationally connected to the axle and rotor discs rotationally connected to the rim. One or more actuators, for example, one or more hydraulic cylinders, are arranged to exert a pressing force on the stack of discs via a hydraulic ring. Each braking action performed by the aircraft pilot causes an increase in the temperature of the brake discs and their immediate surroundings.

[0004] The wheel is conventionally equipped with on-board sensors used for monitoring and maintenance of the lander. Such sensors must be electrically powered in order to function despite the thermal and mechanical stresses imposed by their environment.

[0005] Depending on the installation constraints of these sensors, for example in confined areas or areas with high thermal stress, it is not always possible to run power cables to connect the sensors to a centralized power source, nor to attach a battery system, which is often too bulky and expensive to certify due to confinement constraints (in particular for technical solutions incorporating Lithium).

[0006] SUBJECT OF THE INVENTION

[0007] The invention therefore aims at an arrangement improving the power supply of electrical systems equipping aircraft wheels. Summary of the invention

[0008] To this end, the invention proposes an aircraft wheel comprising a rim equipped with rotor discs driven in rotation with the rim by means of first studs attached to the rim and engaged in notches in the rotor discs, stator discs being interposed between the rotor discs and provided with notches engaged on second studs attached to a fixed brake torsion tube in rotation relative to an axle carrying the wheel.

[0009] According to the invention, the wheel comprises at least one heat exchanger arranged to capture the heat transmitted by the discs to at least one of the first or second studs, and at least one power unit configured to electrically power an electrical system equipping the wheel, the power unit comprising at least one thermoelectric module, one face of which is in contact with the heat exchanger to transform the heat captured by said heat exchanger into an electric current.

[0010] Such an arrangement thus makes it possible to locally transform the heat emitted by the brake discs into an electric current, and therefore to facilitate the supply of the electrical system located on the lander, in particular when said electrical system is in an environment close to the wheel brake.

[0011] According to a particular embodiment of the invention, the heat exchanger comprises at least one sintered heat pipe extending in at least one of the first and second studs substantially parallel to a plane passing through an axis of rotation of the wheel, the heat pipe having one end projecting outside the rim, and at least one first heat sink attached to the end of the heat pipe, the thermoelectric module being in contact with the heat sink.

[0012] In particular, the first heat sink includes fins giving the end of the heat pipe an increased free surface area, the thermoelectric module being in contact with one of the fins.

[0013] Advantageously, the thermoelectric module is arranged between two fins.

[0014] According to a particular feature, the thermoelectric module includes a second face opposite to the first face and on which is disposed a second heat sink giving said thermoelectric module an increased free surface.

[0015] In particular, the electrical system is a measuring sensor.

[0016] In particular, the first tenons came from the material with the rim.

[0017] In particular, the first tenons are bars attached to the rim.

[0018] The invention also relates to an aircraft landing gear comprising at least one such wheel.

[0019] The invention also relates to an aircraft comprising at least one such landing gear. Brief description of the drawings

[0020] The invention will be better understood in the light of the following description, which is purely illustrative and not limiting, and should be read in conjunction with the accompanying drawings, among which:

[0021] [Fig-1] [Fig.1] is a simplified representation of an aircraft including landing gear main rollers having wheels according to the invention;

[0022] [Fig.2] [Fig.2] is an exploded view of one of the aircraft's main landing gear illustrated in [Fig.1] (without its pneumatic system for clarity);

[0023] [Fig.3] [Fig.3] is an axial cross-sectional view of the wheel equipping the lander main one illustrated in [Fig.2];

[0024] [Fig.4] [Fig.4] is a schematic view of a thermoelectric module equipping the wheel illustrated in [Fig.3]. DETAILED DESCRIPTION OF THE INVENTION

[0025] With reference to [Fig.1], the invention applies to an aircraft A comprising main landing gear P each having a leg J ​​having a first end articulated to a structure of the aircraft A and a second end provided with an axle E.

[0026] According to figures 2 and 3, each axle E is provided with a wheel 1 comprising a rim 2 connected by a disc to a hub 3 mounted to rotate on the axle E around an axis X. The rim 2 here comprises two half-rims 2a, 2b which are assembled by bolts 5 and which each have a bead 6 such that a tire can be trapped between the beads 6.

[0027] The wheel 1 is equipped with a brake 10 comprising a stack of discs 11 received in an annular space delimited by the half-rim 2a and the hub 3. The stack of discs 11 is threaded onto a torsion tube 12 fixed to the axle E by bolts. The brake 10 includes a support 13 for brake actuators 14 adapted to selectively apply a braking force to the stack of discs 11. The brake actuators 14 are hydraulic pistons.

[0028] The stack of discs 11 comprises stator discs 1a and rotor discs 11b. The rotor discs 11b have an outer rim provided with notches, in each of which is engaged a first tenon 7 made of material with the half-rim 2a, so that the rotor discs 11b are rotationally linked to said half-rim 2a. The stator discs 1a have an inner rim provided with notches, each receiving a second tenon 15 integral with the torsion tube 12, so that the stator discs 1a are rotationally linked to the torsion tube 12. All of this is well known and is mentioned only to situate the invention.

[0029] Each of the first tenons 7 of the rim 2 includes a non-through hole 7.1, designed to extend along the length of each first tenon 7. A tubular sintered heat pipe 20 is embedded in each of the holes 7.1. The heat pipe 20 extends substantially parallel to the axis X of rotation of the wheel 1 outside the discs 11 but in the immediate vicinity of their peripheral edge, and only one end 20.1 of the heat pipe 20 protrudes outside the hole 7.1 and the half-rim 2a.

[0030] The heat pipe 20 is held in position in the first tenon 7 by hydroforming (hot or cold). Thus, after being inserted into the first tenon 7, the heat pipe 20 is plastically deformed, and the shape of the heat pipe 20 is locally determined by the bore 7.1, which acts as a die. Close contact is thus ensured between the external surface of the heat pipe 20 and the wall of the bore 7.1.

[0031] In order to significantly reduce the contact resistance between the heat pipe 20 and the bore 7.1 of the first tenon 7, a heat-conducting material such as a thermal adhesive, a thermal paste, or a low-temperature expanding metal can be deposited between the heat pipe 20 and the walls of the first tenon 7 defining the bore 7.1. It is understood that in this way the contact is strengthened between the external surface of the heat pipe 20 and the wall of the bore 7.1, promoting heat transfer from one to the other by conduction.

[0032] At the end 20.1 of the heat pipes 20 are arranged a plurality of annular fins 21, each extending in a plane orthogonal to the axis X of rotation of the wheel 1 and centered on the axis X of rotation of the wheel 1. The fins 21 are here spaced from each other at regular intervals and constitute a heat sink giving the end 20.1 of the heat pipe 20 an increased free surface.

[0033] The fins 21 are provided with a plurality of holes, each receiving the end portion 20.1 of each of the heat pipes 20. The fins 21 are attached to the heat pipes 20 by hydroforming after being threaded onto the end portion 20.1 of each heat pipe 20. Thus, the end portion 20.1 of each heat pipe 20 is plastically deformed, and its diameter is locally determined by the diameter of the holes in the fins 21 into which the end portion 20.1 is received. The contact is thus strengthened between the external surface of the heat pipe 20 and the fins 21, promoting heat transfer from one to the other by conduction.

[0034] It is important that the fins 21 do not interfere with the rotation of the wheel 1 or the operation of the brake 10 and its braking actuators 14. Therefore, the fins 21 extend so as to provide sufficient space with respect to the brake 10 and the rim 2. The fins 21, by their annular shape, are arranged to extend around the support 13.

[0035] The heat pipes 20, equipped with fins 21, capture the heat transmitted by the discs 11 to the rim half 2a and transfer it to the fins 21 for dissipation by convection into the ambient air. The heat pipes 20 and the fins 21 thus form a heat exchanger whose arrangement has the advantage of capturing the heat as close as possible to the discs 11 and therefore limiting its diffusion into the rim 2.

[0036] As illustrated in [Fig. 3], the wheel 1 is further equipped with a power supply unit 30 configured to supply electrical power to at least one electrical system (not shown) located on the lander P in the vicinity of the brake 10 of the wheel 1. The electrical system includes, for example, a sensor and / or a communication device. The sensor may be a temperature sensor (for example, for measuring the temperature inside the tire), a stress sensor (for example to measure the shock suffered by the lander P during a landing), a pressure sensor (for example to measure the pressure to which the tire is subjected), a position sensor (for example to measure wear on the discs 11)... The communication device can be a "loT" (Internet of Things) type modem configured to transmit, by radio waves, the signals delivered by the sensor to a control unit located in the cockpit of aircraft A or directly on the ground on a dedicated network, via a remote antenna arranged in the hatch in which the lander P is housed in flight.

[0037] The power supply unit 30 comprises a plurality of thermoelectric modules 31 based on the exploitation of the Seebeck effect, that is, on the appearance of a potential difference at the junction of two conductive materials subjected to a temperature difference. Referring to [Fig. 4], each of the thermoelectric modules 31 is arranged between two fins 21 and conventionally comprises:

[0038] • a first support plate 32.1 and a second support plate 32.2 extending substantially parallel to each other; • a plurality of first legs 33.1 in an n-type semiconductor material and second legs 33.2 in a p-type semiconductor material extending alternately between the first and second plates 32.1, 32.2; • a plurality of interconnecting elements 34 arranged in contact with inner faces of the first and second plates 32.1, 32.2 and connected on one side to a first leg 33.1 and on the other side to a second leg 33.2.

[0039] The inner face of the first plate 32.1 is in contact with the interconnecting elements 34 that connect a first leg 33.1 to a second leg 33.2 in the direction of current flow. The inner face of the second plate 33.2 is in contact with the interconnecting elements 34 that connect a second leg 33.2 to a first leg 33.1 in the direction of current flow. Thus, the first and second legs 33.1, 33.2 are connected to form a series circuit in order to accumulate the potential difference generated by each pair of first and second legs 33.1, 33.2.

[0040] An outer face of the first plate 32.1 is positioned in contact with a lateral side of a fin 21 in order to capture the heat transmitted by the discs 11 to the half-rim 2a via the heat pipes 20 so as to form a so-called "hot" zone. On an outer face of the second plate 32.2 is positioned a heat sink 35 giving said second plate 32.2 an increased free surface area in contact with the ambient air so as to form a so-called "cold" zone.

[0041] In order to ensure optimal contact and avoid the presence of air between the thermal module between the thermoelectric module 31 and the fin 21 on the one hand, and between the thermoelectric module 31 and the heat sink 35 on the other hand, a thermal paste is applied between the outer face of the first plate 32.1 and the lateral side of the fin 21 and between the outer face of the second plate 32.2 and the heat sink 35. A fixing system (for example of the clamp type or bolted assembly) makes it possible to hold the thermoelectric module 31 / heat sink 35 assembly in position on the fin 21, in particular with regard to the centrifugal force to which said assembly is subjected when the wheel 1 rotates.

[0042] The first and second plates 32.1, 32.2 are made of a thermally conductive and electrically insulating material so as to homogenize the temperature gradient to which each leg 33.1, 33.2 is subjected while avoiding uniformizing the electrical potential of the different interconnection elements 34 in contact with the same plate 32.1, 32.2.

[0043] It is understood that a potential difference appears across the terminals of the circuit thus formed when, during braking, the first plate 32.1 captures the heat transmitted by the discs 11 to the half-rim 2a via the heat pipes 20 equipped with the fins 21, so that each thermoelectric module 31 converts the heat released by the brake 10 into an electric current.

[0044] The power supply unit 30 here comprises a first group of three thermoelectric modules 31 connected in series and a second group of three thermoelectric modules 31 also connected in series, the first and second groups being connected in parallel. The terminals 36.1, 36.2 of the circuit formed by the six thermoelectric modules 31 are connected to the electrical system to supply it electrically (if necessary via a slip ring).

[0045] In a known manner, the series connection of the thermoelectric modules 31 makes it possible to increase the voltage of the electric current supplied by the power supply unit 30 and to facilitate its use in the communication device, and the parallel connection of the first and second groups of thermoelectric modules 31 makes it possible to increase the intensity of said electric current and to make its source more reliable in the event of failure or breakage of one or more of the thermoelectric modules 31.

[0046] It should be noted that the arrangement of the thermoelectric modules 31 between the fins 21 allows them to be protected from external aggressions.

[0047] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0048] Although the tenons 7 are here formed from the material with the half-rim 2a, the tenons 7 can also be bars attached to the half-rim 2a and in which the heat pipes 20 are implanted.

[0049] Although the heat pipes 20 are here implanted in tenons attached to the half-rim 2a, they can also be implanted in the tenons 15 attached to the torsion tube 12 (or in bars attached to the torsion tube 12) to capture the heat from the discs 11 and limit its diffusion in said torsion tube 12.

[0050] Although here all the tenons 7 are provided with a heat pipe 20, only a part of the tenons 7 can accommodate a heat pipe 20.

[0051] Although here heat pipes 20 are used to capture the heat transmitted by the discs 11 to the half-rim 2a and to transport it to the first plate 32.1 of the thermoelectric modules 31 via the fins 21, other types of exchangers can be used, in particular those using a phase change material, to extract heat from the brake 10 and ensure the highest possible thermal gradient between the first and second plates 32.1, 32.2 of the thermoelectric modules 31.

[0052] Although the end 20.1 of the heat pipes 20 is here provided with fins 21, other types of heat sink can be used to transport the heat captured by the heat pipe 20 to the first plate 32.1 of the thermoelectric modules 31.

[0053] The number and shape of the fins 21 may differ from those illustrated in [Fig. 1].

[0054] The number of thermoelectric modules 31 may differ from that illustrated in [Fig. 3].

[0055] Although the heat pipes 20 are here implanted horizontally, they can also be slightly inclined and form a non-zero angle with the X axis of rotation of the rim 2 in order to facilitate their operation with respect to gravity.

[0056] The materials used for the thermoelectric modules 31 are well known to those skilled in the art and depend on the operating temperature range.

[0057] Although the end 20.1 of the heat pipe 20 protrudes from the half-rim 2a, the bore 7.1 can also be arranged so that the end of the heat pipe carrying the fins protrudes from the half-rim 2b, particularly in the case of a one-piece rim. The fins 21 and the thermoelectric modules 31 are then arranged inside the half-rim 2b.

[0058] Although here the heat pipe 20 is held in position in the tenon 7 by hydroforming, other methods of fixing can be used (bonding, bolting, additive manufacturing...).

[0059] The thermoelectric modules 31 can be rigid or flexible.

[0060] Although the thermoelectric modules 31 are here connected in series and parallel, they can be connected directly to the electrical system.

[0061] Several thermoelectric modules 31 can be in contact with the same fin 21. For example, two thermoelectric modules 31 can be arranged on the same lateral side of a fin 21. For example again, two thermoelectric modules 31 can be arranged on either side of the same fin 21.

[0062] Although the electrical system here includes a sensor and / or a communication device, any type of electrical system can be powered by the power supply unit 30: brake cooling fan 10, wheel rotation drive device 1, battery...

Claims

Demands

1. Aircraft wheel (1) comprising a rim (2) equipped with rotor discs (11b) driven in rotation with the rim by means of first studs (7) integral with the rim and engaged in notches in the rotor discs, stator discs (1a) being interposed between the rotor discs and provided with notches engaged on second studs (15) integral with a torsion tube (12) of a brake fixed in rotation relative to an axle (4) carrying the wheel, characterized in that the wheel comprises at least one heat exchanger (20, 21) arranged to capture the heat transmitted by the discs to at least one of the first or second studs, and at least one power unit (30) configured to electrically supply an electrical system equipping the wheel,the power supply unit comprising at least one thermoelectric module (31) a first face of which is in contact with the heat exchanger to transform the heat captured by said heat exchanger into an electric current.

2. Aircraft wheel (1) according to claim 1, wherein the heat exchanger comprises at least one sintered heat pipe (20) extending in at least one of the first and second studs substantially parallel to a plane passing through an axis (X) of rotation of the wheel, the heat pipe having one end (20.1) projecting outside the rim (2), and at least one first heat sink (21) integral with the end of the heat pipe, the thermoelectric module (31) being in contact with the heat sink.

3. Aircraft wheel (1) according to claim 2, wherein the first heat sink comprises fins (21) giving the end (20.1) of the heat pipe (20) an increased free surface, the thermoelectric module (31) being in contact with one of the fins.

4. Aircraft wheel (1) according to claim 3, wherein the thermoelectric module (31) is arranged between two fins (21).

5. Aircraft wheel (1) according to any one of the preceding claims, wherein the thermoelectric module (31) comprises a second face opposite the first face and on which is disposed a second heat sink (35) giving said thermoelectric module an increased free surface.

6. Aircraft wheel (1) according to any one of the preceding claims, wherein the electrical system is a measuring sensor.

7. Aircraft wheel (1) according to any one of the preceding claims, wherein the first studs (7) came of material with the rim (2).

8. Aircraft wheel (1) according to any one of the preceding claims, wherein the first studs (7) are bars attached to the rim (2).

9. Aircraft landing gear (P) comprising at least one wheel (1) according to any one of the preceding claims.

10. Aircraft (A) comprising at least one landing gear according to claim 9.

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