EP4182563A1

EP4182563A1 - Ventilation system for aircraft wheel and wheel assembly comprising such a system

Info

Publication number: EP4182563A1
Application number: EP21749673.6A
Authority: EP
Inventors: Patrice Caule; Florent CHALLAS; Thierry Fontalbat; Franck VERDIER; Rémi ESTANOVE
Original assignee: Safran Ventilation Systems SAS
Current assignee: Safran Ventilation Systems SAS
Priority date: 2020-07-20
Filing date: 2021-07-12
Publication date: 2023-05-24
Also published as: WO2022018351A1; US20230349436A1; FR3112580B1; FR3112580A1; CN116324179A

Abstract

One aspect of the invention relates to a ventilation system (100) intended to be mounted in an aircraft wheel along a central axis (XX), and comprising a rotor (140) that is provided with a plurality of blades (143) and is accommodated between a shroud support (150) and a protective grille (120), the shroud support (150) comprising a structural element (160) that is arranged next to an aeraulic element (170), the structural element (160) being metallic and designed to nest in the wheel and support the rotor (140), the aeraulic element (170) being made of plastic or resin and designed to direct a flow of air toward the rotor (140). Another aspect of the invention relates to an aircraft wheel assembly equipped with a ventilation system of this kind.

Description

DESCRIPTION

Ventilation system for an aircraft wheel and wheel assembly comprising such a system

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a ventilation system for an aircraft wheel intended to cool a braking device of the wheel. The invention also relates to a wheel assembly comprising a braking device cooled by such a ventilation system.

The invention finds applications in the field of aircraft landing gear and in particular the cooling of the braking device of these aircraft.

TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Aircraft landing gear generally comprises several wheels, each equipped with a braking device. It is known that a braking device heats up when it is activated. Aircraft braking systems experience very high heating when the aircraft lands due, in particular, to the speed of the aircraft when it arrives on the ground and to its weight. Not only can this heating pose a risk to the integrity of the braking system, but it also has an effect on the profitability of the aircraft. Indeed, the rotation time of an aircraft, i.e. the time during which it must remain on the ground before being able to take off again, is conditioned by the cooling of the landing gear braking devices. An aircraft cannot, for example, leave its parking spot if the temperature of the discs of its braking devices exceeds 300° C. in order to prevent them from breaking in the event of an emergency landing. However, the shorter the turnaround time of an aircraft, the more profitable the aircraft.

[0004] To limit the rotation time of aircraft, it is known to have a fan on the ground, close to the wheels of the aircraft. It is also known to embed a forced ventilation system. This forced ventilation system is generally housed within each wheel of the landing gear. [0005] Ventilation systems for aircraft wheels are known, specially dedicated to the cooling of landing gear braking devices. An example of such a ventilation system is shown schematically in Figures 1 and 2. This ventilation system 11 is generally mounted around a shaft 40 of axis XX, driven by a motor 30, for example an electric motor. The ventilation system 11 generally comprises a rotor 14 equipped with blades intended to mix a flow of air. It also includes a shroud support 15 and a protective grid 12 mounted on either side of the rotor 14 along the axis XX.

[0006] However, current ventilation systems are relatively heavy and relatively noisy. For example, current ventilation systems for single-aisle range aircraft, such as the A319, A320 or A330, weigh around 6.5 kg and generate noise around 100 dB (sound pressure measurement global).

[0007] Recently, new airport standards have been issued which aim to limit environmental noise when aircraft are on the ground, parked or moving on the tarmac ®. These standards aim to limit the noise of an aircraft on the ground to 80 dB, this noise level being measured at the periphery of the aircraft, which allows an intrinsic noise of approximately 85 dB. To date, all known techniques for reducing the noise generated by a ventilation system consist of adding components that have the effect of making the system heavier. However, it is constant, in aeronautics, to seek to limit or reduce the weight of aircraft.

[0008]There is therefore a real need for a ventilation system allowing a gain in the noise level without increasing the mass of the system.

SUMMARY OF THE INVENTION

[0009] To respond to the problems mentioned above of reducing the level of noise generated by ventilation systems without increasing the mass of said system, the applicant proposes a ventilation system in which the shell support is divided into two elements made with different materials, one of the elements being lightened, the two elements being formed so as to improve the aeraulics of the system.

According to a first aspect, the invention relates to a ventilation system intended to be mounted in an aircraft wheel along a central axis and comprising a rotor provided with a plurality of blades and housed between a shroud support and a protective grid. This ventilation system is characterized in that the shroud support comprises a structural element juxtaposed with an aeraulic element, the structural element being metallic and suitable for fitting into the wheel and supporting the rotor, the aeraulic element being plastic and adapted to direct the airflow to the rotor.

This ventilation system makes it possible, by directing the flow of air, to reduce the level of noise generated. It allows, moreover, by a structural modification of certain elements, a gain in mass of the system. Modifications to the ventilation system, compared to the state of the art, also allow an improvement in performance.

[0012] In addition to the characteristics that have just been mentioned in the previous paragraph, the ventilation system according to one aspect of the invention may have one or more additional characteristics from among the following, considered individually or in all technically possible combinations:

- the rotor comprises a band extending circularly at one radial end of the blades, said band comprising a crenellated surface capable of impeding the passage of the air flow, this crenellated surface comprising at least one slot.

- the structural element and the aeraulic element of the shell support are integral with each other.

- the structural element comprises an inner crown, an outer crown and a plurality of arms distributed over the circumference of the inner crown and connecting the inner crown to the outer crown, the inner and outer crowns and the arms comprising rounded contours devoid of ridges.

- the aeraulic element has the shape of a flattened crown comprising, in its centre, a dropped edge adapted to fit the rotor strip.

- the aeraulic element comprises a first face, substantially planar, capable of being attached to the external crown of the structural element.

- the protective grid comprises a shell equipped with a first and a second set of orifices, the first set of orifices facing the blades of the rotor and adapted to allow the flow of air to pass, the second set of orifices facing the central hub of the rotor and adapted to reduce the mass of the protective grid.

- the protective grid comprises a dropped edge extending axially at an outer end of the shell, this raised edge comprising fixing means for fixing said protective grid to the ferrule support.

- it comprises a quarter-turn locking device mounted on the protective grille and the ventilation element to fix said protective grille on the ventilation element of the shell support.

Another aspect of the invention relates to a wheel assembly comprising a wheel mounted on a rim and positioned around a central axis, a wheel braking device and a ventilation system arranged along the central axis to cooling the braking device by circulating a flow of air, the ventilation system being in accordance with that defined above.

[0014] Advantageously, the structural element of the ferrule support is integral with the rim of the wheel.

[0015] In the rest of the description, the term “interior or internal” will be understood to mean the element or the portion of an element closest to the central axis of the system and by “external or external” the element or the portion element farthest from said central axis.

BRIEF DESCRIPTION OF FIGURES

Other advantages and characteristics of the invention will appear on reading the following description, illustrated by the figures in which:

[0017] Figure 1, already described, shows a schematic sectional view of part of a wheel assembly equipped with a ventilation system according to the prior art; Figure 2, already described, shows a sectional view of a ventilation system according to a prior art;

[0019] Figure 3 shows a schematic sectional view of part of a wheel assembly equipped with a ventilation system according to the invention;

Figure 4 shows a sectional side view of the ventilation system according to the invention; [0021] Figure 5 shows a front perspective view and a rear perspective view of the ventilation system according to the invention, mounted on an electric motor;

Figure 6 shows an exploded perspective view of the ventilation system according to the invention, mounted on an electric motor;

Figure 7 shows a rear view and a front view, in perspective, of the ferrule support according to the invention;

Figure 8 shows a front perspective view and a rear perspective view of the ferrule support of Figure 7, mounted on the housing;

Figure 9 shows a side view and a front view of the protective grid according to the invention;

[0026] Figure 10 shows a front perspective view of the ventilation system of Figure 4 when the latter is equipped with a quarter-turn locking device; and

FIG. 11 represents a comparison of performance curves of the ventilation system according to the invention and of the ventilation system of the prior art.

DETAILED DESCRIPTION

[0028] An embodiment of a ventilation system for an aircraft wheel of the single-aisle range, configured to generate a noise level compatible with the new airport standard, is described in detail below, with reference to the drawings. annexed. This example illustrates the characteristics and advantages of the invention. It is however recalled that the invention is not limited to this example.

In the figures, identical elements are identified by identical references. For reasons of legibility of the figures, the size scales between the elements represented are not respected.

A schematic example of an aircraft wheel assembly according to the invention is shown in Figure 3. This wheel assembly 10 is equipped with the ventilation system 100 according to the invention, an example of which is shown in Figure 4. This wheel assembly 10 comprises a rim 20 around which is mounted a tire, not shown in the figure, and within which the ventilation system 100 is mounted. This ventilation system 100, mounted along the central axis XX, around the shaft 40, is driven in rotation by the electric motor 30 in order to suck in the flow of hot air coming from the braking device 50.

The ventilation system 100 comprises a shroud support 150 and a protective grid 120 mounted on either side of a rotor 140. The rotor 140 is mounted integral with the shaft 40, between the shroud support 150, placed inside the wheel, and the protective grid 120, placed partially outside the wheel.

The ferrule support 150 comprises a structural element 160 and an aeraulic element 170, juxtaposed and integral with one another. The structural element 160 is a metal part housed in the rim 20 and whose role is in particular to maintain the ventilation system in the wheel, whatever the stresses of the wheel and in particular the vibration stresses. The aeraulic element 170 is a plastic part, fixed on the structural element 160 and adapted to receive the rotor 140.

An example of the rotor 140 is shown, in a sectional side view, in Figure 4 and, in a perspective view, in Figure 6. This rotor 140, made for example in a plastic material filled with fibers , comprises a central hub 141 mounted on the shaft 40 of the wheel assembly and bordered radially by a skirt 142. It also comprises a plurality of blades 143 which extend radially from the skirt 142 to a band 144. The band 144 is circular and extends coaxially with the skirt 142, at the outer end of the blades 143. The blades 143 are therefore integral with the skirt 142, at their inner end (that is to say the end closest to the central axis XX), and secured to the band 144 at their outer end (that is to say the furthest from said central axis XX).

The headband 144 has the shape of a ring positioned at the outer end of the blades 143. It has an inner surface 144a and an outer surface 144b, the inner surface being in contact with the blades 143, the outer surface being in contact, as explained below, with the protective grid 120 and the aeraulic element 170. The outer surface 144b is crenellated and forms a labyrinth 145 providing axial pressure drops. This labyrinth 145 is formed of a single slot or of several successive slots, for example from one to five slots, which provide a barrier to the flow of air in the directions parallel to the central axis XX so as to favor the passage of the air at the level of the blades 143, between the skirt 142 and the inner surface 144a of the headband. By minimizing the recirculation flow rate of air on the outer surface of the rotor 140, the strip 144 with its labyrinth 145 has the effect of increasing the performance of the ventilation system while reducing the noise level.

The ferrule support 150, an example of which is shown in Figures 7 and 8, is formed of two separate elements 160, 170, fixed to each other, for example by a set of screws 151, as shown in parts B of Figures 7 and 8, or by overmolding. One of these, called structural member 160, is designed to be an integral part of the wheel assembly structure. For this, this structural element 160 is metallic and comprises an inner ring 161, an outer ring 162 and a plurality of arms 163 connecting the inner ring to the outer ring. The inner rim 161 has a suitable circumferential shape to allow the insertion of the structural element into the rim 20 of the wheel assembly. This circumferential shape may be identical to the part of the ferrule support of the prior art intended to be inserted into the rim. The outer ring 162 has the shape of a flat ring, the internal diameter of which is greater than the outer diameter of the inner ring 161. Several arms 163, integral with the two inner 161 and outer 162 rings, are distributed over the circumference of said rings to ensure a certain rigidity to the structure while limiting its mass. Arms and crowns can be made in one piece; they can, on the contrary, be manufactured separately and secured to each other by welding, brazing or any other known means of fixing metal parts. The inner 161 and outer 162 crowns, as well as the arms 163, have rounded contours (or outer lines), devoid of edges, to allow optimal circulation of the air flow and thus improve the aeraulics of the structural element. 160. In other words, the shapes of the inner crown 161, of the outer crown 162 and of the arms 163 are sized to limit losses and to optimize the flow of air entering the rotor 140.

The aeraulic element 170 of the ferrule support 150 is a flattened crown-shaped element whose role is to receive the rotor 140 and to conduct the air flow towards the wheel. For this, the aeraulic element 170 comprises a first face 171 and a second face 172, the first face being in contact with the structural element 160, the second face facing the protective grid 120. The second face 172 may comprise an anfractuous surface, provided with cavities and serrations ensuring a gain in mass. The first face 171 comprises a substantially planar surface, adapted to be attached to the outer crown 162 of the structural element 160 with continuity between the surfaces in contact with the air in order to ensure the guiding of the air flow and limit the loss. The aeraulic element 170 further comprises, in its center, a dropped edge 173 adapted to fit the strip 144 of the rotor. This flanged edge 173 can fit partially around the band 144, for example up to the first crenel of the labyrinth 145. The term “fit” means the fact that the flanged edge 173 surrounds a portion of the band 144, i.e. that is to say that it exactly wraps the circumference of the strip 144 over a predefined width of said strip, for example from the end of the strip to the first slot of the labyrinth 145.

The aeraulic element 170 having no structural role, it can be made of plastic, for example fiber- or non-fibered PEEK (polyetheretherketone), or in a resin, for example based on amorphous thermoplastic polyetherimide such as 'ULTEM®. Indeed, plastics and resins have the advantage of being lighter than metal and easier to shape. Thus, not only is the ferrule support 150, partially made of plastic or resin, lighter than the ferrule support of the prior art, but it also improves cooling by guiding the flow of air towards the rotor 140. In addition, the fact that the ventilation element is made of plastic or resin makes it possible to optimize the clearance between the flange 173 and the strip 144 so as to adjust the fit of the ventilation element 170 on the rotor 140 and, thus, preventing noise from being generated by the operating clearance.

[0038] Furthermore, the production in two parts of the ferrule support 150 offers an additional advantage: in the event of a violent impact, the aeraulic element 170 and the rotor 140 can come into contact with each other without risk of broken. Since both parts are made of plastic or resin, the risk of rotor breakage is less than in current ventilation systems where the rotor collides with a metal ferrule support. In addition, during maintenance of the aircraft, it is possible to change only one of the two elements, which limits maintenance costs.

In some embodiments, such as that shown in Figures 7 and 8, the ventilation element 170 and the outer ring 162 of the structural element 160 may each include a radial opening 152, facing one of the 'other, to allow the passage of a cable, for example for checking the tire pressure, the edges 152a, 152b of the opening of the outer ring 162 being connected by a jumper 153

As shown in Figures 5 and 6, the rotor 140 is housed between the ferrule support 150, which has just been described, and the protective grid 120. The protective grid 120, an example of which is shown according to a side view (drawings A) and a front view (drawing B) in FIG. 9, comprises a shell 121 made of sheet metal, equipped with a first and a second set of orifices 122, 123. The shell 121 has a substantially basin shape with a circular bottom 121a which extends in a radial plane and an edge 121b which extends axially around the circumference of the bottom 121a.

[0041] The edge 121b of the shell 121 has a substantially flat outer face, that is to say without roughness, so as to optimize the ventilation of the protective grid 120. It further comprises a face which extends circumferentially opposite the labyrinth 145 of the rotor 140. This internal face of the edge 121b may comprise one or more crenellations of a shape complementary to the crenellations of the outer surface 144b of the band 144 so as to together form a barrier to the airflow. The fact of hindering the circulation of air between the rotor 140 and the protective grid 120 outside the rotor 140 not only makes it possible to optimize the air flow inside the rotor, but also to reduce the level of noise. generated by air circulation.

The bottom 121a of the hull 121 is equipped with a first set of orifices 122 and a second set of orifices 123. The orifices of the first set of orifices 122 are opposite the blades 143 of the rotor and are adapted to let the air flow through. These holes are as large as possible so as to let in as much air as possible. Each orifice of the first set of orifices 122 can, for example, have a substantially square shape. The spacing arms between two consecutive orifices are chosen as thin as possible so as to limit the level of noise generated by the flow of air on these spacing arms. In fact, the more discreet the presence of the spacer arms, the fewer obstacles there are to the right of the aeraulics and therefore the less the air flow generates noise.

The orifices 123 of the second set of orifices are housed in the central zone of the bottom 121a and adapted to reduce the mass of the protective grid. These orifices 123, positioned for example opposite the central hub 141 of the rotor 140, can have an oblong shape making it possible to accommodate a maximum of orifices and therefore to limit the mass of the protective grid as much as possible.

The dimensions of the orifices and the dimensions of the spacings between orifices are determined according to the thickness of the sheet forming the shell 121. To limit the mass of the ventilation system as much as possible, the sheet of the shell 121 is chosen the as thin as possible, for example 2.5 mm thick. For a very thin sheet, for example 2.5 mm, reinforcements 124 between the orifices 122 of the first set of orifices and the orifices 123 of the second set of orifices can be provided regularly on the circumference of the zone of the shell containing the orifices. These reinforcements 124 make it possible to ensure the solidity of the protective grid 120 to allow the holding of the shaft 40 in its central zone 125.

The protective grid 120 comprises, on its circumference, a raised edge 126 extending axially along the ventilation element 170 of the ferrule support. This raised edge 126 forms a partial crown around the shell 121 intended to receive fixing means for fixing the protective grid to the ferrule support. These fixing means may comprise, for example, several holes 128 adapted to receive fixing screws and/or studs. For example, the central holes 128a can be adapted to receive the pins 165 of the ferrule support 150 and the off-center holes 128b can be adapted to receive screws or fixing bolts 166.

According to certain embodiments, the ventilation system comprises a quarter-turn locking device 180 making it possible to fix the protective grid 120 on the ventilation element 170 of the shroud support. An example of a quarter-turn locking device is shown in Figure 10 in an unlocked position (drawing A) and in a locked position (drawing B). This quarter-turn locking device 180, more simply called a locking device, comprises a notch 181 made on the second face 172 of the aeraulic element 170 and a tab 182 made on the raised edge 126 of the protective grid 120, said tongue 182 being able to fit into the notch 181. The locking device 180 may also comprise one or more sets of studs 183 and oblong orifices 184 distributed over the circumference of the protective grid 120 and of the element aeraulic 170 to facilitate the assembly of the protection grid 120 against the ventilation element 170. In this variant, the stud 183 can protrude from the ventilation element 170 or from the structural element 160 via a hole in the ventilation element, the stud of the locking device 180 can then be the nipple 165 described above. This quarter-turn locking device 180 makes it possible, by a simple rotation, to lock or unlock the protective grid. One or two screws or bolts 166 can complete the locking device 180 and be mounted through the protective grille 120, the aeraulic element 170 and the structural element 160 for safety reasons, in particular due to the vibrations undergone by the ventilation system. Even with one or two screws or bolts 185, this protection grid 120 is much simpler to assemble and disassemble than the protection grid of the prior art which requires the screwing/unscrewing of nine bolts. This embodiment of the protective grid saves considerable time during assembly or disassembly (for example during the maintenance phase) of the protective grid and limits the risk of loss of screws and/or bolts.

FIG. 11 represents examples of curves showing the air flow supplied by the ventilation system to a wheel assembly according to the prior art and according to the invention. These curves are represented in a frame where the abscissa axis corresponds to the air flow passing through the ventilation system and the ordinate axis corresponds to the pressure rise generated by the ventilation system. Curves C3 and C4 show the actual performance of an aircraft in the single-aisle range, old generation and new generation respectively. Curve C5 shows the air requirements of these aircraft. Curve C1 shows the rise in pressure of the ventilation system according to the prior art. Curve C2 shows the rise in pressure of the ventilation system according to the invention. The intersection of curves C2 with C3 or C4 shows that the ventilation system according to the invention allows an air flow of approximately 110 and 140 liters respectively, which exceeds the air requirement of 100 liters (curve C5) of these aircraft. The ventilation system of the invention can therefore be installed on any aircraft of the single-aisle range. Thus, this ventilation system, which makes it possible to reduce the intrinsic sound level to about 85 dB (which corresponds to about 80 dB at the periphery of the aircraft) offers an air flow sufficient for the needs of the aircraft, without increasing its mass.

[0048] Although described through a certain number of examples, variations and embodiments, the aircraft wheel ventilation system according to the invention comprises various variations, modifications and improvements which will be apparent to those skilled in the art, it being understood that these variations, modifications and improvements fall within the scope of the invention.

Claims

[Claim 1] Ventilation system (100) intended to be mounted in an aircraft wheel along a central axis (XX) and comprising a rotor (140) provided with a plurality of blades (143) and housed between a shroud (150) and a protective grid (120), characterized in that the shroud support (150) comprises a structural element (160) juxtaposed with an aeraulic element (170), the structural element (160) being metallic and adapted to fit into the wheel and support the rotor (140), the aeraulic element (170) being made of plastic or resin and adapted to direct a flow of air towards the rotor (140).

[Claim 2] Ventilation system according to claim 1, characterized in that the rotor (140) comprises a band (144) extending circularly at a radial end of the blades (143), said band comprising a crenellated surface (145) capable of hindering the passage of the air flow, this crenellated surface comprising at least one slot.

[Claim 3] Ventilation system according to claim 1 or 2, characterized in that the structural element (160) and the aeraulic element (170) of the shroud support are integral with one another.

[Claim 4] Ventilation system according to any one of the claims

1 to 3, characterized in that the structural element (160) comprises an inner ring (161), an outer ring (162) and a plurality of arms (163) distributed over the circumference of the inner ring and connecting the inner ring to the outer crown, the inner (161) and outer (162) crowns and the arms (163) having rounded contours devoid of edges.

[Claim 5] Ventilation system according to any one of the claims

2 to 4, characterized in that the aeraulic element (170) has the shape of a flattened crown comprising, in its center, a dropped edge (173) adapted to fit the strip (144) of the rotor.

[Claim 6] Ventilation system according to claims 4 and 5, characterized in that the aeraulic element (170) comprises a first face (171), substantially planar, adapted to be attached to the outer crown (162) of the structural element.

[Claim 7] Ventilation system according to any one of Claims 1 to 6, characterized in that the protective grid (120) comprises a shell (121) equipped with a first and a second set of orifices ( 122, 123), the first set of orifices (122) being opposite the blades of the rotor and adapted to allow the flow of air to pass, the second set of orifices (123) being opposite a hub (141) of the rotor and adapted to reduce the mass of the protective grid.

[Claim 8] Ventilation system according to Claim 7, characterized in that the protective grid (120) comprises a raised edge (126) extending axially at an outer end of the shell (121), this raised edge comprising fixing means for fixing said protective grid (120) to the ferrule support (150).

[Claim 9] Ventilation system according to claim 8, characterized in that it comprises a quarter-turn locking device (180) mounted on the protective grille (120) and the aeraulic element (170) to fix the said grille protection on the aeraulic element of the shell support.

[Claim 10] Wheel assembly (10), comprising:

- a wheel mounted on a rim (20) and positioned around a central axis (XX),

- a braking device (50) of the wheel, and

- a ventilation system (100) arranged along the central axis to cool the braking device by circulation of an air flow, characterized in that the ventilation system (100) conforms to any one of the claims 1 to 9.

[Claim 11] Wheel assembly according to Claim 10, characterized in that the structural element (160) of the ferrule support is integral with the rim (20) of the wheel.