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

Abstract

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 for pivoting 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 disc; a wheel rotation drive device (40), comprising an electric actuator extending axially opposite an outer face of the disc; and a cooling device (50) for the brake discs and the electric actuator, comprising a fan (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.FIGURE DE L’ABREGE: Fig. 3A.

Description

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

[0001] 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 device for the drive device and the braking device.

[0002] BACKGROUND OF THE INVENTION

[0003] In the field of aviation, it is known to equip aircraft wheels with a friction brake designed to selectively slow down and stop said aircraft when they are moving on the ground. The brake generally comprises a stack of discs consisting of alternating rotor and stator discs, housed inside the wheel rim. The heat generated by the friction of the discs against each other during braking can be significant, particularly during landing where the energy to be dissipated is high due to the aircraft's mass and high speed.

[0004] It is also now planned to equip aircraft braked wheels with a rotating drive element 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.

[0005] 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 various states. 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 very 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 aeronautical components and products that are less energy-intensive, more environmentally friendly, and whose integration and use in civil aviation have moderate environmental consequences, with the aim of improving the energy efficiency of aircraft.

[0006] 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.

[0007] This sustained research and development work focuses on new generations of aircraft engines, the lightening of aircraft, in particular 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.

[0008] The aircraft braked wheel drive unit generally comprises an electric motor mounted coaxially at one end of the axle, the brake disc stack and the electric motor extending on either side of the wheel rim.

[0009] It has been envisaged that the brake and drive unit could be cooled by a cooling device comprising a single single-speed fan coupled to a ferrule extending around the drive unit and the fan, the ferrule being attached to the wheel to guide the airflow generated by the fan. The cooling device allows for strong ventilation of the brake during parking phases and also of the drive unit during taxiing phases, thus reducing the aircraft's downtime and limiting the self-heating of the electric motor.

[0010] However, such a cooling device 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 the taxiing phases, which can lead to oxidation of the brake discs, especially after a landing where their temperature is particularly high.

[0011] SUBJECT OF THE INVENTION

[0012] The invention therefore aims to provide a braked and motorized wheel comprising a cooling device that at least partially overcomes the aforementioned drawback. Summary of the invention

[0013] To this end, an aircraft wheel mounted for rotation on an axle is proposed. The wheel comprises: • 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 into the annular space opposite an inner face of the sail; • a wheel rotation drive device, comprising an electric actuator extending axially opposite an external face of the disc; and • a cooling device 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.

[0014] According to the invention, the cooling device further comprises an air inlet delimited by the ferrule and arranged axially between the rim and the fan, and a movable air inlet closure system arranged so that said air inlet can adopt an open state and a closed state.

[0015] Thus, when the air inlet is open and the fan is activated, a small proportion of the air drawn in by the fan comes from the hot air emitted by the brake discs, and a large proportion of said air comes from ambient air drawn in through the air inlet. This allows for minimal ventilation of said discs and cooling of the electric actuator of the drive device. The minimal ventilation of the brake discs during a taxiing phase following landing or taxi braking helps to limit oxidation of said brake discs.

[0016] Conversely, when the air inlet is closed and the fan is activated, the air drawn in by the fan comes mainly from the hot air released by the brake discs, which allows strong ventilation of the discs and therefore accelerated cooling of said discs, making it possible to limit the time the aircraft is immobilized between two flights.

[0017] It is understood that the sealing system allows the cooling of the brake to be separated from that of the electric actuator.

[0018] According to a particular feature, the air inlet includes an annular slot.

[0019] In particular, the annular slot is delimited by a free end of the ferrule and a peripheral edge of a crown fixed to the rim.

[0020] In particular, the air inlet closure system comprises a ring mounted axially sliding on the ferrule between an open position in which the ring 61 is recessed from the air inlet so that said air inlet is in the open state, and a closed position in which the ring obstructs the air inlet so that said air inlet is in the closed state, the sliding of the ring being achieved by means of an actuator.

[0021] In particular, the actuator is controlled by a control unit arranged to bring the ring into the open position when the wheel is turning and into the closed position when the wheel is stopped.

[0022] In particular, the air inlet closure system comprises a plurality of elastically deformable slats between a rest state and a deformed state, the slats being juxtaposed and each comprising a first end fixed to the peripheral edge of the ring and a second end, opposite to the first end, provided with a weight which, in the rest state, is a support against the ferrule so that the slat obstructs the air inlet and which, in the deformed state, is away from the ferrule so that the slat releases the air inlet, the slats having an elasticity such that they are in the rest state when the wheel is at rest and in the deformed state when the wheel rotates, each of the weights undergoing the effect of the centrifugal force generated by the rotation of the wheel.

[0023] According to another particular characteristic, the fan is a single-speed fan.

[0024] The invention also relates to an aircraft landing gear comprising at least one such wheel.

[0025] The invention also relates to an aircraft comprising at least one such landing gear.

[0026] The invention further relates to a method for cooling the braking device and the drive device of such an aircraft wheel, the method comprising the following steps: • when the wheel rotates, the air inlet opens via the shutter system and the fan is activated to ventilate the electric actuator through the air inlet; and • when the wheel is stationary and the brake discs have a temperature above a predetermined temperature, the air inlet is closed via the shutter system and the fan is activated to ventilate the brake discs through the air passages formed by the holes in the disc. Brief description of the drawings

[0027] 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:

[0028] [Fig-1] [Fig.1] is a simplified view of an aircraft including landing gear main ones equipped with wheels according to the invention;

[0029] [Fig.2] [Fig.2] is a schematic view of the wheels of the main landing gear of the aircraft illustrated in [Fig.1];

[0030] [Fig.3A] [Fig.3A] is a schematic axial cross-sectional view of one of the wheels according to the invention illustrated in [Fig.2], in which the sealing system of the cooling device is in the open position;

[0031] [Fig.3B] [Fig.3B] is a view identical to [Fig.3A], in which the shutter system of the cooling device is in the closed position;

[0032] [Fig.4A] [Fig.4A] is a perspective view of a first embodiment of the wheel illustrated in [Fig.3A], in which the sealing system of the cooling device is in the open position;

[0033] [Fig.4B] [Fig.4B] is a view identical to [Fig.4A], in which the shutter system of the cooling device is in the closed position;

[0034] [Fig.5A] [Fig.5A] is a perspective view of a second embodiment of the wheel illustrated in [Fig.3A], in which the sealing system of the cooling device is in the open position;

[0035] [Fig. 5B] [Fig. 5B] is a view identical to [Fig. 5A], in which the shutter system of the cooling device is in the closed position. DETAILED DESCRIPTION OF THE INVENTION

[0036] With reference to [Fig. 1], the invention is described in application to an aircraft 1 comprising two main landers 2. Each of the main landers 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 landers 2 are here of the retractable type, but the invention is applicable to fixed landers, or even to another type of vehicle such as a land vehicle.

[0037] The following description relates to one of the aircraft's 2 landing gears, the 2 landing gears being identical here but also being different.

[0038] With reference to [Fig. 3A], the inner wheel 10a and the outer wheel 10b each comprise 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.

[0039] The inner wheel 10a and the outer wheel 10b each define: • 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. • 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.

[0040] The veil 12 has holes 12.1 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.

[0041] The inner wheel 10a and the outer wheel 10b are said to be "braked," that is, each equipped with a braking device 20 intended 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 inside the first annular space 10.1 of the wheel 10a, 10b and are axially opposite the outer face of the wheel rim 12.

[0042] 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 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.

[0043] As illustrated in [Fig. 2], the outer wheel 10b is equipped with a cooling device 30 for its brake discs 21. The cooling device 30 includes a fan generally called a BCF (for "Brake Cooling Fan").

[0044] 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.

[0045] 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, in this case: • a stator coupled to axle 5 such that the stator is stationary relative to said axle 5; and • 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.

[0046] The internal wheel 10a is further equipped with a cooling device 50 for its braking device 20 and its drive device 40.

[0047] The cooling device 50 comprises a fan 51 extending coaxially with the body 41 of the drive device 40 such that said body 41 is arranged axially between the rim 11 and said fan 51. The fan 51 is controlled by a control unit and comprises blades driven in rotation by a geared motor 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 motor of the inner wheel 10a. The fan 51 is here a single-speed "on / off" type fan.

[0048] The cooling device 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.

[0049] 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 putting into fluidic communication the cylindrical space 52.3 delimited by the ferrule 52 with the outside of said ferrule 52.

[0050] 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 of said ferrule 52.

[0051] The air inlet E formed by the annular slot 52.5 is selectively in an open state (illustrated in [Fig.3A]) or in a closed state (illustrated in [Fig.3B]) by means of a movable shuttering system 60 of said annular slot 52.5.

[0052] With reference to Figures 4A and 4B, the sealing system 60 includes a ring 61 for masking the air inlet E. The ring 61 is axially slidably mounted on the ferrule 52 between an open position in which the ring 61 is recessed from The air inlet E is then in the open state ([Fig. 4A]), and a second closed position in which the ring 61 substantially obstructs the air inlet E, which is then in the closed state ([Fig. 4B]). The sliding of the ring 61 is achieved by means of a dedicated masking actuator (not shown): the sealing system 60 is said to be active.

[0053] The masking actuator is controlled by the control unit which is arranged to implement the following cooling process: • during taxiing or ground handling phases, in other words when the aircraft 1 is moving on the ground via the drive device 40, the masking ring 61 of the air inlet E is brought, via the masking actuator, into its open position so that the air inlet E is in the open state, and the fan 51 is activated; and • during parking phases between landing and takeoff, in other words when the aircraft 1 is at a standstill, the masking ring 61 of the air inlet E is brought, via the masking actuator, into its closed position so that the air inlet E is in the closed state, and the fan 51 is activated as long as the temperature of the brake discs 21 is above a predetermined temperature.

[0054] The performance of the cooling device 50 therefore differs between the taxiing and parking phases: • During taxiing phases, the opening of air inlet E and the activation of fan 51 result in: • a slight cooling of the brake discs 21 by 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; • an intake of ambient air via the air inlet E formed by the annular slot 52.5; • Cooling of the electric motor of the drive device 40 by drawing in the hot air emitted by said electric motor and by the airflow combining the drawing in of hot air from the brake discs 21 and the drawing in of ambient air; and • 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. • During parking phases, closing the air inlet E and activating the fan 51 results in: • strong cooling of the brake discs 21 by drawing in the hot air released by said brake discs 21 through the air passages P formed by the holes 12.1 in the wheel disc 12; and • an evacuation of this hot 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.

[0055] It is understood that during taxiing phases, 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-in air comes from ambient air drawn in through the air inlet E formed by the annular slot 52.5. This allows for low ventilation of said discs 21 and cooling of the electric motor of the drive device 40, thereby limiting the self-heating of said electric motor. The low 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.

[0056] Conversely, during parking phases, the air drawn in by the fan 51 comes almost exclusively 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.

[0057] Figures 5A and 5B illustrate a movable obturator system 60' which is simply an alternative to the obturator system 60. The obturator system 60' comprises a plurality of identical and elastically deformable blades 61' between a rest state ([Fig. 5B]) and a deformed state ([Fig. 5A]). The blades 61' are juxtaposed and each comprises a first end fixed to a peripheral edge of the crown 16, and a second end, opposite the first end, provided with a weight 61.1' which: • in its resting state, it rests against the skirt 52.2 of the ferrule 52 so that the slat 61.1' obstructs the air inlet E formed by the annular slot 52.5; and • in the deformed state, is away from the skirt 52.2 of the ferrule 52 so that the slat 61.1' releases the air inlet E formed by the annular slot 52.5.

[0058] In the resting state, the slats 61.1' together cause a substantially total occlusion of the air inlet E, which is then in the closed state. In the deformed state, the slats 61.1' release the air inlet E, which is then in the open state.

[0059] The slats 61.1' have an elasticity such that they are in the rest state when the internal wheel 10a is at rest, and in the deformed state when the internal wheel 10a rotates around the axis X, each of the weights 61.1' undergoing the effect of the centrifugal force generated by the rotation of the internal wheel 10a.

[0060] It is therefore understood that when the aircraft 1 is moving on the ground, the air inlet E formed by the annular slot 52.5 is in the open state, and that when the aircraft 1 is at rest, the said air inlet is in the closed state: the shuttering system 60' is said to be passive.

[0061] The performance of the cooling device 50 therefore differs between the taxiing and parking phases: • During taxiing phases, the release of air inlet E by the slats 61.1' and the activation of fan 51 result in: • a slight cooling of the brake discs 21 by 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; • an intake of ambient air via the air inlet E formed by the annular slot 52.5; • Cooling of the electric motor of the drive device 40 by drawing in the hot air released by said electric taxiing motor and by the airflow combining the drawing in of hot air from the brake discs 21 and the drawing in of ambient air; and • 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. • During parking phases, the blocking of the air intake by the slats 61.1' and the activation of the fan 51 result in: • strong cooling of the brake discs 21 by drawing in the hot air released by said brake discs 21 through the air passages P formed by the holes 12.1 in the wheel disc 12; and • an evacuation of this hot 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.

[0062] It is understood that during taxiing phases, 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-in air comes from ambient air drawn in through the air inlet E formed by the annular slot 52.5. This allows for low ventilation of said discs 21 and cooling of the electric motor of the drive device 40, thereby limiting the self-heating of said electric motor. The low 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.

[0063] Conversely, during parking phases, the air drawn in by the fan 51 comes almost exclusively 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.

[0064] 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.

[0065] Although the fan 51 is here a single-speed fan, it can also be a variable-speed fan.

[0066] The proportion of ambient air drawn in by the fan can be adapted according to the performance requirements of the cooling device 50 by bringing the masking ring 61 of the air inlet E into an intermediate position between the open position and the closed position to reduce / increase the passage area of ​​the air inlet E and thus adapt the proportion of ambient air drawn in according to the requirements.

[0067] 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 device 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.

[0068] Instead of being elastically deformable, the slats 61.1' can be motorized.

[0069] The electric motor of the drive device 40 can be replaced by a geared motor.

[0070] The outer wheel 10b can be identical to the inner wheel 10a and be equipped with a drive device 40, a cooling device 50 provided with a sealing system 60, 60' to mask an air inlet E arranged between the outer wheel 10b and the body 41 of the drive device 40.

[0071] The outer wheel 10b may not be braked.

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 for pivoting on the axle, the rim defining 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 disc; - a drive device (40) for rotation of the wheel, comprising an electric actuator extending axially opposite an outer face of the disc;and - a cooling device (50) for the brake discs and the electric actuator, comprising a fan (51) extending axially opposite the electric actuator so 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 device further comprising an air inlet (E) delimited by the ferrule and arranged axially between the rim and the fan, and a movable closing system (60, 60') for the air inlet arranged so that said air inlet can adopt an open state and a closed state.;

2. Aircraft wheel (10a) according to claim 1, wherein the air inlet (E) includes an annular slot (52.5).

3. Aircraft wheel (10a) according to claim 2, wherein the annular slot (52.5) ​​is delimited by a free end of the ferrule (52) and a peripheral edge of a crown (16) fixed to the rim (11).

4. Aircraft wheel (10a) according to claim 3, wherein the air inlet (E) closure system (60) comprises a ring (61) axially mounted to slide on the ferrule (52) between an open position in which the ring (61) is recessed from the air inlet such that said air inlet is in the open state, and a closed position in which the ring obstructs the air inlet such that

5.

6.

7.

8.

9.

10. said air inlet is in the closed state, the sliding of the ring being achieved by means of a masking actuator. Aircraft wheel (10a) according to claim 4, wherein the masking actuator is controlled by a control unit arranged to bring the ring into the open position when the wheel is rotating and into the closed position when the wheel is stationary. Aircraft wheel (10a) according to claim 3, wherein the air inlet (E) closure system (60') comprises a plurality of elastically deformable slats (61') between a rest state and a deformed state, the slats being juxtaposed and each comprising a first end fixed to the peripheral edge of the ring (16) and a second end, opposite the first end, provided with a weight (61).1') which, in the rest state, is a support against the ferrule (52) so that the slat obstructs the air inlet and which, in the deformed state, is away from the ferrule so that the slat releases the air inlet, the slats having an elasticity such that they are in the rest state when the wheel is at rest and in the deformed state when the wheel rotates, each of the weights undergoing the effect of the centrifugal force generated by the rotation of the wheel. Aircraft wheel (10a) according to any one of the preceding claims, wherein the fan is a single-speed fan. Aircraft landing gear (2) comprising at least one wheel (10a) according to any one of the preceding claims. Aircraft (1) comprising at least one landing gear (2) according to claim 8. Method for cooling the braking device (20) and the drive device (40) of an aircraft wheel (10a) according to any one of claims 1 to 7, the method comprising the following steps: • when the wheel (10a) rotates, the air inlet (E) opens via the shutter system (60, 60') and the fan (51) is activated to ventilate the electric actuator via the air inlet (E); and • when the wheel (10a) is stationary and the brake discs (21) have a temperature above a certain temperature predetermined, closure of the air inlet (E) via the shutter system (60, 60') and activation of the fan (51) to drive ventilation of the brake discs via the air passages (P) formed by the holes (12.1) of the web (12).

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