Aircraft wheel comprising a drive device, a braking device and a system for cooling the drive device and the braking device

Abstract

The invention relates to an aircraft wheel (10a) rotatably mounted on an axle (5), comprising: - an annular rim (11) connected by a web (12) to a hub (13) pivotably received on the axle, the rim delimiting with the hub an annular space partially closed by the web which comprises through-holes (12.1) forming air passages (P); - a braking device (20) comprising brake discs (21) extending in the annular space facing an inner face of the web; - a device (40) for driving the rotation of the wheel, comprising an electric actuator extending axially facing an outer face of the web; and - a system (50, 50', 50'') for cooling the brake discs and the electric actuator, comprising a fan (51, 51', 51'') extending axially facing the electric actuator, and a shroud (52) extending around the drive device and the fan.

Description

[0001] Description

[0002] Title of the invention: Aircraft wheel comprising a drive device, a braking device, and a cooling system for the drive device and the braking device

[0003] The present invention relates to the braking and ground movement of an aircraft and, more particularly, an aircraft wheel comprising a drive device, a braking device and a cooling system for the drive device and the braking device.

[0004] BACKGROUND OF THE INVENTION

[0005] In aviation, it is common practice to equip aircraft wheels with a friction brake designed to selectively slow down and stop aircraft while they are moving on the ground. The brake typically consists of a stack of discs, including alternating rotor and stator discs, housed inside the wheel rim. The heat generated by the friction of the discs during braking can be significant, particularly during landing, where the energy to be dissipated is high due to the aircraft's mass and speed.

[0006] It is now also planned to equip aircraft braked wheels with a rotating drive unit to allow aircraft to move on the ground without using their powertrains, which has the effect of reducing the carbon footprint during this phase of ground movement.

[0007] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by different countries. In particular, an ambitious standard applies to both new types of aircraft and those already in service, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been actively contributing to the fight against climate change for several years now. Technological research efforts have already led to significant improvements in the environmental performance of aircraft.The Applicant takes into consideration the factors impacting all phases of design and development in order to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental consequences with the aim of improving the energy efficiency of aircraft.

[0008] Consequently, the Applicant is constantly working to reduce its negative climate impact by using methods and operating virtuous development and manufacturing processes that minimize greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0009] This sustained research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to provide propulsion, and, as essential complements to technological progress, aviation biofuels.

[0010] The drive mechanism for aircraft braked wheels typically includes an electric motor mounted coaxially at one end of the axle, with the brake disc stack and the electric motor each extending from one side of the wheel rim. A cooling system comprising a single-speed fan coupled to a ferrule extending around both the drive mechanism and the fan has been considered. The ferrule is attached to the wheel to guide the airflow generated by the fan. This cooling system allows for strong ventilation of the brake during parking and of the drive mechanism during taxiing, thereby reducing the aircraft's downtime for cooling and limiting the self-heating of the electric motor.

[0011] However, such a cooling system does not allow the cooling of the brake to be separated from that of the electric motor, so that strong ventilation of the brake is imposed during taxiing phases, which can lead to oxidation of the brake discs, especially after a landing where their temperature is particularly high.

[0012] SUBJECT OF THE INVENTION

[0013] The invention therefore aims to provide a braked and motorized wheel including a cooling system which at least partially overcomes the aforementioned drawback.

[0014] SUMMARY OF THE INVENTION

[0015] For this purpose, an aircraft wheel mounted for rotation on an axle is proposed, comprising:

[0016] - an annular rim connected by a disc to a hub received by pivoting on the axle, the rim delimiting with the hub an annular space partially closed by the disc which includes through holes forming air passages; - a braking device comprising brake discs extending in the annular space opposite an inner face of the disc;

[0017] - a wheel rotation drive device, comprising an electric actuator extending axially opposite an external face of the wheel; and

[0018] - a cooling system for the brake discs and the electric actuator, comprising a fan extending axially opposite the electric actuator so that said electric actuator extends axially between the rim and the fan, and a ferrule extending around the drive device and the fan.

[0019] According to the invention, the cooling system further comprises an air inlet delimited by the ferrule and arranged axially between the rim and the fan, and an electronic fan control unit arranged to rotate fan blades at a first non-zero speed to cool at least the drive device, and at a second non-zero speed different from the first speed to cool the braking device, the first speed inducing an airflow, from the air inlet (E) and the air passages (P), sufficient to cool the electric actuator and the second speed inducing an airflow, from the air passages (P), sufficient to cool the brake discs.

[0020] Preferably, the electronic fan control unit is arranged to rotate the fan blades at the first speed when the wheel is driven in rotation by the drive device, and at the second speed when the wheel is stationary and the brake discs have a temperature above a predetermined temperature.

[0021] However, there could be phases where the wheel is driven without activating the cooling system. For example, during taxiing phases, the cooling system could be activated only once the vehicle moves away from the parking area, to avoid blowing air near ground personnel (to detect this distance, a speed or distance threshold could be used, or even position information on the runway).

[0022] Similarly, conversely, if high temperatures are reached in the actuator at the end of taxiing, it could continue to be cooled while the aircraft is stationary.

[0023] Thus, during taxiing, the fan can be activated to cool the electric actuator of the drive system and provide low-level ventilation to the brake discs, thereby limiting their oxidation. Conversely, during parking, the fan can be activated to provide high-level ventilation to the brake discs, resulting in accelerated cooling and thus reducing the aircraft's downtime between flights.

[0024] It is understood that the cooling system allows the cooling of the braking device to be separated from that of the drive device.

[0025] According to a particular feature, the electronic control unit connects the fan to a three-phase network, the fan comprising blades driven in rotation by a three-phase geared motor.

[0026] Specifically, the second speed is higher than the first speed, with the direction of rotation of the fan blades being identical in both speeds. The electronic control unit includes a rectifier connected to the three-phase network, an inverter connecting the fan geared motor to the rectifier and supplying an output current to the geared motor, and an inverter control unit configured to deliver a control signal at a frequency corresponding to the inverter's output current. This control signal represents either a zero frequency or a frequency corresponding to the first or second speed of rotation of the fan blades.

[0027] In particular, the geared motor comprises a motor with two independent or separate windings, and in which the electronic control unit includes a control box arranged to connect the three-phase network to one of the windings in order to rotate the fan blades at the first speed, or to the other of the windings in order to rotate said fan blades at the second speed.

[0028] According to another particular characteristic, the first speed is substantially equal, in absolute value, to the second speed, the blades having opposite directions of rotation to the first speed and the second speed.

[0029] In particular, the fan blades are shaped to cause low ventilation of said brake discs at the first speed and high ventilation of said discs at the second speed.

[0030] In particular, the air inlet includes an annular slot delimited by a free end of the ferrule and a peripheral edge of a crown fixed to the rim.

[0031] The invention also relates to an aircraft landing gear comprising at least one such wheel.

[0032] The invention also relates to an aircraft comprising at least one such landing gear.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood in light of the following description, which is purely illustrative and not limiting, and should be read in conjunction with the accompanying drawings, among which:

[0034] [Fig. 1] Figure 1 is a simplified view of an aircraft comprising main landing gear equipped with wheels according to the invention;

[0035] [Fig. 2] Figure 2 is a schematic view of the wheels of the main landing gear of the aircraft illustrated in Figure 1;

[0036] [Fig. 3] Figure 3 is an axial cross-sectional view of one of the wheels according to the invention illustrated in Figure 2;

[0037] [Fig. 4A] Figure 4A is a schematic view of the cooling system, according to a first embodiment, of the wheel illustrated in Figure 3;

[0038] [Fig. 4B] Figure 4B is a schematic view of the cooling system, according to a second embodiment, of the wheel illustrated in Figure 3;

[0039] [Fig. 4C] Figure 4C is a schematic view of the cooling system, according to a third embodiment, of the wheel illustrated in Figure 3.

[0040] DETAILED DESCRIPTION OF THE INVENTION

[0041] With reference to Figure 1, the invention is described in application to an aircraft 1 comprising two main landing gears 2. Each of the main landing gears 2 has a leg 3 having a first end articulated to a structure 4 of the aircraft 1 and, at the opposite end, a second end carrying two wheels (an inner wheel 10a and an outer wheel 10b) rotating about an axis X on a tubular shaft or axle 5. The main landing gears 2 are here of the retractable type, but the invention is applicable to fixed landing gear, or even to another type of vehicle such as a ground vehicle. The following description relates to one of the aircraft's landing gears 2; the landing gears 2 are identical here but may also be different.

[0042] Referring to Figure 3, the inner wheel 10a and the outer wheel 10b each have an annular rim 11 connected to a hub 13 by a disc 12. The rim 11 receives a tire 14 and has distal ends with annular flanges (not shown) extending radially outward from the wheel 10 to form axial stops preventing the tire 14 from coming off the rim. The hub 13 is pivotally supported on the axle 5 by means of bearings 15.

[0043] The inner wheel 10a and the outer wheel 10b each define:

[0044] - a first internal annular space 10.1, delimited by a first internal surface of the rim 11, an internal face of the disc 12 and a first external surface of the hub 13 extending opposite the first internal surface of the rim 11.

[0045] - a second external annular space 10.2, delimited by a second inner surface of the rim 11, an external face of the web 12 (opposite to the inner face of said web 12) and a second external surface of the hub 13 extending opposite the second inner surface of the rim 11.

[0046] The veil 12 has holes 12.1, commonly called alveoli, distributed symmetrically around the axis X and extending each along an axis substantially parallel to said axis X to open on either side of the veil 12. The holes 12.1 form air passages P putting into fluidic communication the first annular space 10.1 and the second annular space 10.2.

[0047] The inner wheel 10a and the outer wheel 10b are said to be "braked," that is, each equipped with a braking device 20 designed to selectively slow down and stop the aircraft 1 when it is on the ground. The braking device 20 comprises brake discs 21, including stator discs and rotor discs, which are stacked alternately against each other on a torsion tube 22 fixed to the axle 5. The torsion tube 22 and the stack of discs 21 extend within the first annular space 10.1 of the wheel 10a, 10b and are axially aligned with the outer face of the wheel rim 12.

[0048] The braking device 20 further includes a ring 23 fixed to one end of the torsion tube 22. The ring 23 includes a plurality of cavities which are distributed symmetrically around the X axis and each receiving a braking actuator 24 which selectively exerts a pressing force, parallel to the X axis, on the stack of discs 21. The pressing force generates friction between the stator discs and the rotor discs, which results in the application of a braking torque on the wheel 10a, 10b and a temperature rise of the brake discs 21.

[0049] As illustrated in Figure 2, the outer wheel 10b is equipped with a cooling device 30 for its brake discs 21. The cooling device 30 includes a fan (not shown) commonly referred to as a BCF (for "Brake Cooling Fan").

[0050] Unlike the outer wheel 10b, the inner wheel 10a is said to be "motorized", that is to say, equipped with a rotating drive device 40 intended to move the aircraft 1 without using its power-driven propulsion units when it is on the ground.

[0051] The drive device 40 comprises a body 41, generally cylindrical in shape, extending coaxially from the axle 5, axially opposite the outer face of the wheel disc 12, and outside the second annular space 10.2. The body 41 defines a drive zone for the inner wheel 10a and includes an electric actuator (not shown) comprising an electric motor having:

[0052] - a stator coupled to axle 5 such that the stator is stationary relative to said axle 5; and

[0053] - a rotor mounted to rotate on the stator around the X axis and linked in rotation to the hub 13 by means of an interface element 42 so as to transmit the torque of said rotor to the internal wheel 10a.

[0054] The internal wheel 10a is further equipped with a cooling system 50 for its braking device 20 and its drive device 40.

[0055] The cooling system 50 comprises, according to a first embodiment of the invention, a fan 51 extending coaxially with the body 41 of the drive device 40 such that said body 41 is arranged axially between said fan 51 and the rim 11. The fan 51 comprises blades 51.1 driven in rotation by a three-phase geared motor 51.2 to generate an airflow substantially parallel to the X-axis so as to extract the heat emitted by the brake discs 21 and the electric actuator of the inner wheel 10a. The geared motor 51.2 is controlled by an electronic control unit 53 connecting said geared motor 51.2 to a three-phase network 6 of the aircraft 1. The three-phase network 6 has a fixed frequency.

[0056] The cooling system 50 also includes a ferrule 52 extending coaxially around the fan 51 and the body 41 of the drive device 40. The ferrule 52 comprises a circular front wall 52.1 extending in a plane perpendicular to the X-axis, and a skirt 52.2 extending axially projecting from a peripheral edge of the front wall, towards the internal wheel 10a. The front wall 52.1 and the skirt 52.2 together define a cylindrical space 52.3 in which the fan 51 and the body 41 of the drive device 40 extend, such that the ferrule 52 forms a protective housing for the fan 51 and the drive device 40, and guides the airflow generated by said fan 51.

[0057] The front wall 52.1 of the ferrule 52 is provided with through holes 52.4 which are distributed symmetrically around the axis X to form air outlets S putting into fluidic communication the cylindrical space 52.3 delimited by the ferrule 52 with the outside of said ferrule 52.

[0058] The skirt 52.2 includes a free end which delimits, with a crown 16 fixed coaxially to the rim 11 and extending in the continuation of one end of said rim 11, an annular slot 52.5 forming an air inlet E putting into fluidic communication the second annular space 10.2 delimited by the inner wheel 10a and the cylindrical space 52.3 delimited by the ferrule 52 with the outside of said wheel 10a and said ferrule 52.

[0059] With reference to Figure 4A, the electronic control unit 53 of the geared motor 51.2 of the fan 51 comprises:

[0060] - a rectifier 53.1 connected to the three-phase network 6 of aircraft 1;

[0061] - an inverter 53.2 connecting the geared motor 51.2 to the rectifier 53.1 and delivering an output current supplying said geared motor 51.2; and

[0062] - a control box 53.3 of the inverter 53.2 arranged to deliver a control signal Sc of the frequency of the output current of the inverter 53.2 as a function of a first input signal SEI and a second input signal SEE received by the control box 53.3.

[0063] The first SEI input signal is binary and adopts a high state called "on" corresponding to a ventilation command of the electric actuator of the drive device 40, for example, when said electric actuator drives the internal wheel 10a in rotation, or a low state called "off" corresponding to the non-rotation of the internal wheel 10a by the drive device 40.

[0064] The second input signal SE2 is binary and adopts a high state called "on" corresponding to a ventilation order for the discs 21 of the braking device 20 given here by the pilot of aircraft 1, or a low state called "off" corresponding to the absence of a ventilation order for the discs 21 of the braking device 20.

[0065] The Sc control signal is a three-state signal:

[0066] - a first state called "off" corresponding to a zero frequency of the output current of the inverter 53.2;

[0067] - a second state, called "low speed," corresponding to a first non-zero frequency of the inverter's output current 53.2; and

[0068] - a third state called "high speed" corresponding to a second non-zero frequency of the output current of the inverter 53.2, the second frequency being greater than the first frequency.

[0069] The control box 53.3 of the inverter 53.2 is arranged so that the control signal S c either :

[0070] - in the "high speed" state when the second input signal SE2 is in the "on" state;

[0071] - in the "low speed" state when the first SEI input signal and the second SEE input signal are respectively in the "on" state and in the "off" state;

[0072] - in the "off" state when the first SEI input signal and the second SEE input signal are in the "off" state.

[0073] It is understood that the fan 51 is a two-speed fan capable of operating at a first speed Vi and a second speed V2 for the rotation of its blades 51.1. The first speed Vi and the second speed V2 are non-zero and correspond respectively to the first and second frequencies of the output current delivered by the inverter 53.2, such that the second speed V2 is greater than the first speed Vi. It should be noted that the direction of rotation of the blades 51.1 of the fan 51 is the same at both the first speed Vi and the second speed V2.

[0074] The electronic control unit 53 of the geared motor 51.2 of the fan 51 is thus arranged to implement, for example, the following process:

[0075] - during taxiing or ground handling phases, in other words when the aircraft 1 moves on the ground via the drive device 40, activation of the fan 51 to rotate its blades 51.1 at the first speed Vi; and

[0076] - during parking phases between a landing and a takeoff, in other words when the aircraft 1 is at a standstill and the pilot orders the ventilation of the discs 21 of the braking device 20, activation of the fan 51 to rotate its blades 51.1 at the second speed V2 as long as the temperature of the brake discs 21 is above a predetermined temperature.

[0077] The performance of the cooling system 50 therefore differs between taxiing and parking phases:

[0078] - During taxiing phases, activation of fan 51 at the first speed V2 results in:

[0079] • a slight cooling of the brake discs 21 caused by a slight suction of the hot air released by said brake discs 21 via the air passages P formed by the holes 12.1 of the wheel rim 12;

[0080] • intake of ambient air via the air inlet E formed by the annular slot 52.5; • cooling of the electric actuator of the drive device 40 generated by intake of the hot air released by said electric actuator, and by the combined intake of ambient air and hot air from the brake discs 21; and

[0081] • an evacuation of the air sucked in by the fan 51 via the air outlets S formed by the holes 52.4 passing through the front wall 52.1 of the ferrule 52.

[0082] - During parking phases, activating fan 51 at the second speed V2 results in:

[0083] • strong cooling of the brake discs 21 generated by a strong suction of the hot air released by said brake discs 21 via the air passages P formed by the holes 12.1 of the wheel rim 12;

[0084] • an intake of ambient air via the air inlet E formed by the annular slot 52.5; and

[0085] • an evacuation of the air sucked in by the fan 51 via the air outlets S formed by the holes 52.4 passing through the front wall 52.1 of the ferrule 52.

[0086] It is understood that during taxiing phases, the airflow is lower. A small proportion of the air drawn in by the fan 51 comes from the hot air released by the brake discs 21, and a large proportion of said air comes from ambient air drawn in through the air inlet E formed by the annular slot 52.5. This allows for limited ventilation of said discs 21 and cooling of the electric actuator of the drive device 40, thus limiting the self-heating of said electric actuator. The limited ventilation of the brake discs 21 during a taxiing phase following landing or taxi braking also helps to limit the oxidation of said brake discs 21.Conversely, during parking phases, the airflow is higher, a large proportion of the air sucked in by the fan 51 comes from the hot air released by the brake discs 21, which allows strong ventilation of the discs 21 and therefore accelerated cooling of said discs 21 making it possible to limit the immobilization time of the aircraft 1 between two flights.

[0087] Figure 4B illustrates a cooling system 50' which is simply a second embodiment of the cooling system 50. The cooling system 50' differs from the cooling system 50 in that the fan 51 and its electronic control unit 53 are replaced by a fan 51' controlled by an electronic control unit 53''.

[0088] The fan 51' comprises blades 51.1' driven in rotation by a three-phase geared motor 51.2' to generate an airflow substantially parallel to the X-axis in order to extract the heat emitted by the brake discs 21 and the electric actuator of the inner wheel 10a. The geared motor 51.2' is controlled by the electronic control unit 53' which connects said geared motor 51.2' to the three-phase network 6 of the aircraft 1.

[0089] The geared motor 51.2' comprises a motor I with two independent windings or a motor II with two separate windings for driving the blades 51.1' of the fan 51' in rotation at a first speed Vi' and a second speed V2' from the three-phase network 6 of the aircraft 1. The first speed Vi' and the second speed V2' are non-zero, and said second speed V2' is greater than said first speed Vi'. It should be noted that the direction of rotation of the blades 51.1' of the fan 51' is the same at the first speed Vi' and at the second speed V2'.

[0090] The motor I, II comprises a first winding Ei' having three first poles Pi', and a second winding Ei' having three second poles PE'. The first poles Pi' and the second poles PE' are switchable.

[0091] The electronic control unit 53' includes a control box 53.3' of the geared motor 51.2' arranged to selectively connect the first poles Pi' or the second poles P2' of the geared motor 51.2' to the three-phase network 6 of the aircraft 1 according to a first input signal SEI' and a second input signal SE2' received by the control box 53.3'.

[0092] When the first poles Pi' of the first winding Ei' are connected to the three-phase network 6 of aircraft 1, the blades 51.1' of the fan 51' rotate at the first speed Vi'. When the second poles P2' of the second winding E2' are connected to the three-phase network 6 of aircraft 1, the blades 51.1' of the fan 51' rotate at the second speed V2'. It is understood that the fan 51' is a two-speed fan, the control box 53.3' of the geared motor 51.2' of the fan 51' being arranged so that the blades 51.1' of the fan 51' rotate:

[0093] - at zero speed when the first input signal SEI' and the second input signal SEE' are in the "off" state;

[0094] - at the first speed Vi', called "low speed", when the first input signal SEI' and the second input signal SEE' are respectively in the "on" state and the "off" state; and

[0095] - at the second speed VE' called "high speed" when the second input signal SEE' is in the "on" state.

[0096] The electronic control unit 53' of the geared motor 51.2' of the fan 51' is thus arranged to implement, for example, the following process:

[0097] - during taxiing or ground handling phases, in other words when the aircraft 1 moves on the ground via the drive device 40, activation of the fan 51' to rotate its blades 51.1' at the first speed Vi'; and

[0098] - during parking phases between a landing and a takeoff, in other words when the aircraft 1 is at a standstill and the pilot orders the ventilation of the discs 21 of the braking device 20, activation of the fan 51' to rotate its blades 51.1' at the second speed V2' as long as the temperature of the brake discs 21 is above a predetermined temperature.

[0099] The performance of the 50' cooling system therefore differs between taxiing and parking phases:

[0100] - During taxiing phases, activation of fan 51' at first speed Vi' results in:

[0101] • a slight cooling of the brake discs 21 caused by a slight suction of the hot air released by said brake discs 21 via the air passages P formed by the holes 12.1 of the wheel rim 12;

[0102] • an intake of ambient air via the air inlet E formed by the annular slot 52.5;

[0103] • Cooling of the electric actuator of the drive device 40, generated by drawing in the hot air emitted by said electric actuator, and by the combined drawing in of ambient air and hot air from the brake discs 21; and

[0104] • an evacuation of the air sucked in by the fan 51' via the air outlets S formed by the holes 52.4 passing through the front wall 52.1 of the ferrule 52.

[0105] - during parking phases, the activation of the fan 51' at the second speed V2' results in: • strong cooling of the brake discs 21 by a strong suction of the hot air released by said brake discs 21 via the air passages P formed by the holes 12.1 of the wheel rim 12;

[0106] • an intake of ambient air via the air inlet E formed by the annular slot 52.5; and

[0107] • an evacuation of the air sucked in by the fan 51' via the air outlets S formed by the holes 52.4 passing through the front wall 52.1 of the ferrule 52.

[0108] It is understood that during taxiing phases, the airflow is lower. A small proportion of the air drawn in by the fan 51' comes from the hot air released by the brake discs 21, and a large proportion of said drawn air comes from ambient air drawn in through the air inlet E formed by the annular slot 52.5. This allows for limited ventilation of said discs 21 and cooling of the electric actuator of the drive device 40, thus limiting the self-heating of said electric actuator. The limited ventilation of the brake discs 21 during a taxiing phase following landing or taxi braking also helps to limit the oxidation of said brake discs 21.

[0109] Conversely, during parking phases, the airflow is higher, a large proportion of the air sucked in by the fan 51' comes from the hot air released by the brake discs 21, which allows strong ventilation of the discs 21 and therefore accelerated cooling of said discs 21 making it possible to limit the immobilization time of the aircraft 1 between two flights.

[0110] Figure 4C illustrates a cooling system 50'' which is simply a third embodiment of the cooling system 50. The cooling system 50'' differs from the cooling system 50 in that the fan 51 and its electronic control unit 53 are replaced by a fan 51'' controlled by an electronic control unit 53''.

[0111] The fan 51'' comprises blades 51.1'' driven in rotation by a geared motor 51.2'' to generate an airflow substantially parallel to the X-axis in order to extract the heat released by the brake discs 21 and the electric actuator of the internal wheel 10a. The fan 51'' is here a reversible fan capable of adopting a first speed Vi'' of rotation of the blades 51.1'' in one direction and a second speed V2'' of rotation of the blades 51.1'' in the other direction, so that the direction of the airflow generated by the fan 51'' is reversed between the first speed Vi'' and the second speed V2''. The first speed Vi'' and the second speed V2'' are non-zero and said second speed V2 is, in absolute value, substantially equal to the first speed Vi'': the direction of rotation of the blades 51.1'' of the fan 51'' at the first is the inverse of that at the second speed V2''.We understand that the 51'' fan is a two-speed fan.

[0112] The blades 51.1'' of the fan 51'' are shaped to cause a low ventilation of said discs 21 at the first speed Vi'', and a high ventilation of said discs 21 at the second speed V2''.

[0113] The electronic control unit 53' ' includes a control box 53.3' ' of the geared motor 51.2' ' arranged to selectively connect the geared motor 51.2' ' to the three-phase network 6 of the aircraft 1 according to a first input signal SEI' ' and a second input signal SE2' ' received by the control box 53.3' '.

[0114] The first input signal SEI' ' is binary and adopts a high state called "on" corresponding to a ventilation command of the electric actuator of the drive device 40, for example, when said electric actuator drives the internal wheel 10a in rotation, or a low state called "off" corresponding to the non-drive in rotation of the internal wheel 10a by the drive device 40.

[0115] The second input signal SE2' ' is binary and adopts a high state called "on" corresponding to a ventilation order for the discs 21 of the braking device 20 given here by the pilot of aircraft 1, or a low state called "off" corresponding to the absence of a ventilation order for the discs 21 of the braking device 20.

[0116] The control box 53.3'' of the geared motor 51.2'' of the fan 51'' is arranged to connect said geared motor 51.2'' to the three-phase network 6 of the aircraft so that the blades 51.1'' of the fan 51'' rotate:

[0117] - at zero speed when the first input signal SEI' ' and the second input signal SEE' ' are in the "off" state;

[0118] - at the first speed Vi' ' when the first input signal SEI' ' and the second input signal SEE' ' are respectively in the "on" state and the "off" state; and

[0119] - at the second speed VE' ' when the second input signal SEE' ' is in the "on" state.

[0120] The electronic control unit 53'' of the geared motor 51.2'' of the fan 51'' is thus arranged to implement, for example, the following process:

[0121] - during taxiing or ground handling phases, in other words when the aircraft 1 moves on the ground via the drive device 40, activation of the fan 51' to rotate its blades 51.1'' at the first speed Vi"; and

[0122] - during parking phases between a landing and a takeoff, in other words when the aircraft 1 is at a standstill and the pilot orders the ventilation of the discs 21 of the braking device 20, activation of the fan 51' ' to rotate its blades 51.1' ' at the second speed V2' ' as long as the temperature of the brake discs 21 is above a predetermined temperature.

[0123] The performance of the 50'' cooling system therefore differs between taxiing and parking phases:

[0124] - During taxiing phases, activation of fan 51'' at first speed Vi'' results in:

[0125] • a slight cooling of the brake discs 21 caused by a slight suction of the hot air released by said brake discs 21 via the air passages P formed by the holes 12.1 of the wheel rim 12;

[0126] • an intake of ambient air via the air inlet E formed by the annular slot 52.5;

[0127] • Cooling of the electric actuator of the drive device 40, generated by drawing in the hot air emitted by said electric actuator, and by the combined drawing in of ambient air and hot air from the brake discs 21; and

[0128] • an evacuation of the air sucked in by the fan 51 via the air outlets S formed by the holes 52.4 passing through the front wall 52.1 of the ferrule 52.

[0129] - During parking phases, activating fan 51'' at the second speed V2'' results in:

[0130] • strong cooling of the brake discs 21 generated by a strong suction of the hot air released by said brake discs 21 via the air passages P formed by the holes 12.1 of the wheel rim 12;

[0131] • an intake of ambient air via the air inlet E formed by the annular slot 52.5; and • an exhaust of the air drawn in by the fan 51' ' via the air outlets S formed by the holes 52.4 passing through the front wall 52.1 of the ferrule 52.

[0132] It is understood that during taxiing phases, the airflow is lower. A small proportion of the air drawn in by the fan 51 comes from the hot air released by the brake discs 21, and a large proportion of said drawn air comes from ambient air drawn in through the air inlet E formed by the annular slot 52.5. This allows for limited ventilation of said discs 21 and cooling of the electric actuator of the drive device 40, thus limiting the self-heating of said electric actuator. The limited ventilation of the brake discs 21 during a taxiing phase following landing or taxi braking also helps to limit the oxidation of said brake discs 21.

[0133] Conversely, during parking phases, the airflow is higher, a large proportion of the air sucked in by the fan 51' ' comes from the hot air released by the brake discs 21, which allows strong ventilation of the discs 21 and therefore accelerated cooling of said discs 21 making it possible to limit the immobilization time of the aircraft 1 between two flights.

[0134] 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.

[0135] Although the air inlet E is here defined by a space separating the free end of the skirt 52.2 of the ferrule 52 and the ring 16 fixed to the rim 11, it can be axially arranged and shaped differently between the rim 11 and the fan 51 of the cooling system 50. For example, the air inlet E can be defined by at least one hole provided in the skirt 52.2 of the ferrule 52.

[0136] The electric motor of the drive device 40 can be replaced by a geared motor.

[0137] The electronic control unit 53 of the geared motor 51.2 of the fan 51 may include a current reducer.

[0138] The outer wheel 10b can be identical to the inner wheel 10a and be equipped with a drive device 40 and a cooling system 50, 50', 50''.

[0139] The outer 10b wheel may not be braked.

[0140] Although low and high ventilation are achieved here using a two-speed fan, they can also be achieved using a single-speed fan and varying:

[0141] - the pitch of the blades,

[0142] - the geometry of a diffuser for the airflow generated by the fan,

[0143] - the section for the air outlet passage S,

[0144] - the shape of the blades

Claims

DEMANDS 1. Aircraft wheel (10a) mounted for rotation on an axle (5), comprising: - an annular rim (11) connected by a disc (12) to a hub (13) received to pivot on the axle, the rim delimiting with the hub an annular space partially closed by the disc which includes through holes (12.1) forming air passages (P); - a braking device (20) comprising brake discs (21) extending in the annular space opposite an inner face of the sail; - a wheel rotation drive device (40), comprising an electric actuator extending axially opposite an external face of the disc; and - a cooling system (50, 50', 50'') for the brake discs and the electric actuator, comprising a fan (51, 51', 51'') extending axially opposite the electric actuator such that said electric actuator extends axially between the rim and the fan, and a ferrule (52) extending around the drive device and the fan, the cooling system further comprising an air inlet (E) delimited by the ferrule and arranged axially between the rim and the fan, and an electronic control unit (53, 53', 53'') for the fan arranged to rotate fan blades (51.1, 51.1', 51.1'') at a first non-zero speed (Vi, Vi', Vi'') to cool at least the drive device, and at a second speed (V2, V2' , V2' ' ) non-zero and different from the first speed to cool the braking device, the first speed inducing an airflow, from the air inlet (E) and the air passages (P), sufficient to cool the electric actuator and the second speed inducing an airflow, from the air passages (P), sufficient to cool the brake discs.

2. Aircraft wheel (10a) according to claim 1, wherein the electronic control unit (53, 53', 53'') of the fan (51, 51', 51'') is arranged to rotate the blades (51.1, 51.1', 51.1'') of said fan at the first speed (Vi, Vi', Vi'') when the wheel is driven into rotation by the drive device (40), and at the second speed (V2, V2', V2'') when the wheel is stationary and the brake discs (21) have a temperature above a predetermined temperature.

3. Aircraft wheel (10a) according to claim 1 or 2, wherein the electronic control unit (53, 53', 53'') connects the fan (51, 51', 51'') to a three-phase network (6), the fan comprising blades driven in rotation by a three-phase geared motor (51.2, 51.2', 51.2'').

4. Aircraft wheel (10a) according to claim 3, wherein the second speed (V2, V2') is greater than the first speed (Vi, Vi'), the direction of rotation of the blades (51.1, 51.1') of the fan (51, 51') being identical in first speed and second speed.

5. Aircraft wheel (10a) according to claim 4, wherein the electronic control unit (53) comprises a rectifier (53.1) connected to the three-phase network (6), an inverter (53.2) connecting the geared motor (51.2) of the fan (51) to the rectifier and delivering an output current supplying said geared motor, and a control box (53.3) of the inverter arranged to deliver a control signal (Sc) of a frequency of the output current of the inverter, the control signal being representative of a zero frequency or of a frequency corresponding to the first speed (Vi) or the second speed (V2) of rotation of the blades (51.1) of the fan (51).

6. Aircraft wheel (10a) according to claim 4, wherein the geared motor (51.2') comprises a motor with two independent or separate windings (Ei', E2'), and wherein the electronic control unit (53') comprises a control box (53.3') arranged to connect the three-phase network (6) to one of the windings in order to rotate the blades (51.1') of the fan (51') at the first speed (Vi'), or to the other of the windings in order to rotate said blades (51.1') of the fan (51') at the second speed (V2').

7. Aircraft wheel (10a) according to any one of claims 1 to 3, wherein the first speed (Vi'') is substantially equal, in absolute value, to the second speed (V2''), the blades (51.1'') having directions of rotation opposite to the first speed (Vi'') and the second speed (V2'').

8. Aircraft wheel (10a) according to claim 7, wherein the blades (51.1'') of the fan (51'') are shaped to cause low ventilation of said brake discs (21) at first speed (Vi'') and high ventilation of said discs at second speed (V2'').

9. Aircraft wheel (10a) according to any one of the previous claims, wherein the air inlet (E) comprises an annular slot (52.5) ​​delimited by a free end of the ferrule (52) and a peripheral edge of a ring (16) fixed to the rim (11).

10. Aircraft landing gear (2) comprising at least one wheel (10a) according to any one of the preceding claims.

11. Aircraft (1) comprising at least one landing gear (2) according to claim 10.

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