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

Abstract

One aspect of the invention relates to a ventilation system (100) intended to be installed 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 support (150) and a protective grid (120), the shroud support (150) comprising a structural element (160) arranged alongside a hydraulic element (170), the structural element (160) being metallic and designed to be nested in the wheel and to support the rotor (140), the hydraulic element (170) being made of plastic or resin and designed to direct an air flow towards the rotor. Another aspect of the invention relates to an aircraft wheel assembly fitted with such a ventilation system.

Description

Technical Field

[0001] This invention relates to a ventilation system for aircraft wheels, designed to cool devices used for brake wheels. The invention also relates to wheel assemblies comprising brake devices cooled by such a ventilation system.

[0002] This invention is applied to the field of aircraft landing gear, and in particular, to the cooling of the braking devices of these aircraft. Background Technology

[0003] Aircraft landing gear typically comprises several wheels, each equipped with a braking device. These braking devices are known to heat up when actuated. During aircraft landing, the braking devices undergo extremely high temperatures, particularly due to the speed at which the aircraft impacts the ground and its mass. This overheating not only jeopardizes the integrity of the braking system but also impacts the aircraft's profitability. In fact, the aircraft's turnaround time (i.e., the time the aircraft must remain on the ground before it can take off again) is regulated by cooling the landing gear braking devices. For example, if the brake disc temperature exceeds 300°C, the aircraft cannot leave its parking position to prevent the brake discs from rupturing in the event of an emergency landing. However, the shorter the aircraft's turnaround time, the more profitable it is.

[0004] To limit aircraft turnaround time, it is known to place fans on the ground near the aircraft wheels. It is also known to have onboard forced ventilation systems. These forced ventilation systems are typically housed within each wheel of the landing gear.

[0005] Ventilation systems for aircraft wheels are known, particularly those specifically designed for cooling landing gear brakes. An example of such a ventilation system is schematically shown in Figures 1 and 2. The ventilation system 11 is typically mounted around a shaft 40 along axis XX, which is driven by a motor 30 (e.g., an electric motor). The ventilation system 11 typically includes a rotor 14 with blades for agitating the airflow. It also includes shroud supports 15 and protective grilles 12, mounted along axis XX to each side of the rotor 14.

[0006] However, current ventilation systems are relatively heavy and relatively noisy. For example, current ventilation systems used in single-aisle aircraft (such as those in the A319, A320, or A330) weigh approximately 6.5 kg and produce a noise level of approximately 100 dB (based on total sound pressure level measurements).

[0007] Recently, it has been announced that when the aircraft is on the ground, in a parking area, or on the runway... New airport standards, aimed at limiting environmental noise, are being implemented as aircraft move around the world. These standards aim to limit ground noise to 80 dB, a level measured around the aircraft's perimeter, allowing for an inherent noise level of approximately 85 dB. To date, all known techniques for reducing noise generated by ventilation systems have involved adding components, resulting in a heavier system. However, in aeronautics, attempting to limit or reduce the mass of an aircraft is an ongoing practice.

[0008] Therefore, there is indeed a need for a ventilation system that allows for a gain in noise level without increasing the system mass. Summary of the Invention

[0009] To address the aforementioned problem of reducing the noise level generated by the ventilation system without increasing the system's mass, the applicant provides a ventilation system in which the shield support is divided into two elements made of different materials, one of which is lightened to form the two elements in order to improve the system's airflow.

[0010] According to a first aspect, the present invention relates to a ventilation system for mounting along a central axis in an aircraft wheel and including a rotor equipped with a plurality of blades and housed between a shroud support and a protective grille. The ventilation system is characterized by the fact that the shroud support includes a structural element juxtaposed with a ventilation element, the structural element being made of metal and adapted to interlock with the wheel and support the rotor, and the ventilation element being made of plastic and adapted to guide airflow toward the rotor.

[0011] This ventilation system reduces noise levels by guiding airflow. Furthermore, it allows for gains in system mass through structural modifications to certain components. Compared to existing technologies, these changes to the ventilation system also allow for performance improvements.

[0012] In addition to the features just discussed in the preceding paragraphs, a ventilation system according to one aspect of the invention may have one or more of the following additional features, either individually or in any technically possible combination:

[0013] - The rotor includes a belt that extends circularly at the radial end of the blade, the belt including a blunt serrated surface capable of impeding the flow of air, the blunt serrated surface including at least one blunt serration.

[0014] -The structural components and ventilation components of the protective cover support are integrated into one unit.

[0015] - The structural element includes an inner ring, an outer ring, and multiple arms distributed on the circumference of the inner ring and connecting the inner ring to the outer ring. The inner ring, the outer ring, and the arms have a circular profile without ridges.

[0016] - The ventilation element has a flat crown shape, the crown shape including a flanged edge at its center, the flanged edge being adapted to the belt of an interlocking rotor.

[0017] - The ventilation element includes a substantially flat first surface that can engage with the outer ring of the structural element.

[0018] - The protective grille includes a housing with a first set of ports and a second set of ports, the first set of ports facing the rotor blades and adapted to allow airflow through, and the second set of ports facing the central hub of the rotor and adapted to reduce the mass of the protective grille.

[0019] - The protective grille includes a flanged edge extending axially at the outer end of the housing, and the flanged edge includes attachment means for attaching the protective grille to the cover support.

[0020] It includes a locking device with a right-angle (quarter) rotation that is mounted to the protective grille and the ventilation element, as well as a ventilation element for attaching the protective grille to the cover support.

[0021] Another aspect of the invention relates to a wheel assembly comprising: a wheel mounted on a rim and positioned about a central axis; means for braking the wheel; and a ventilation system arranged along the central axis for cooling the braking means by circulating airflow, the ventilation system being a ventilation system as defined above.

[0022] Advantageously, the structural elements of the housing support are integrated with the wheel rim.

[0023] In the remainder of this specification, the term "internal" or "inner" will be understood to refer to the element or part of an element closest to the central axis of the system, and the term "external" or "outer" will be understood to refer to the element or part of an element furthest from the central axis. Attached Figure Description

[0024] Further advantages and features of the invention will become clear from the following description by way of example in the accompanying drawings, in which:

[0025] Figure 1, already described, shows a schematic cross-sectional view of a portion of a wheel assembly equipped with a ventilation system according to the prior art;

[0026] Figure 2, already described, shows a cross-sectional view of a ventilation system according to the prior art;

[0027] Figure 3 shows a schematic cross-sectional view of a portion of a wheel assembly provided with a ventilation system according to the present invention;

[0028] Figure 4 shows a cross-sectional side view of the ventilation system according to the present invention;

[0029] Figure 5 shows a front perspective view and a rear perspective view of a ventilation system installed on an electric motor according to the present invention;

[0030] Figure 6 shows an exploded perspective view of a ventilation system installed on an electric motor according to the present invention;

[0031] Figure 7 shows the rear and front views of the protective cover support according to the present invention in perspective view;

[0032] Figure 8 shows the front and rear perspective views of the protective cover support of Figure 7 installed on the housing;

[0033] Figure 9 shows a side view and a front view of the protective grille according to the present invention;

[0034] Figure 10 shows a front perspective view of the ventilation system of Figure 4 when it is equipped with a right-angle rotary locking device; and

[0035] Figure 11 shows a comparison of the performance curves of the ventilation system according to the present invention and the ventilation system of the prior art. Detailed Implementation

[0036] An exemplary embodiment of a ventilation system for a single-aisle aircraft wheel is described in detail below with reference to the accompanying drawings. This ventilation system is configured to generate a noise level compatible with new airport standards. This embodiment illustrates the features and advantages of the invention. However, it should be noted that the invention is not limited to this embodiment.

[0037] In the accompanying drawings, the same elements are labeled with the same reference numerals. For the sake of readability, the dimensional proportions between the elements shown are not strictly observed.

[0038] Figure 3 shows a schematic embodiment of an aircraft wheel assembly according to the invention. The wheel assembly 10 is provided with a ventilation system 100 according to the invention, an embodiment of which is shown in Figure 4. The wheel assembly 10 includes a rim 20, a tire (not shown) mounted around the rim 20, and the ventilation system 100 mounted within the rim. The ventilation system 100, mounted along a central axis XX around a shaft 40, is rotatably driven by an electric motor 30 to draw in a flow of hot air from a braking device 50.

[0039] The ventilation system 100 includes a shroud support 150 and a protective grille 120 mounted on each side of the rotor 140. The rotor 140 is integrally mounted with the shaft 40 between the shroud support 150 located inside the wheel and the protective grille 120 located partially outside the wheel.

[0040] The shield support 150 includes a structural element 160 and a ventilation element 170 that are juxtaposed and integral with each other. The structural element 160 is a metal piece housed in the rim 20, and its function is primarily to ensure that the ventilation system remains within the wheel, regardless of wheel stress, and particularly, vibration stress. The ventilation element 170 is a plastic piece attached to the structural element 160 and adapted to receive the rotor 140.

[0041] An embodiment of the rotor 140 is shown in the side sectional view of Figure 4 and the perspective view of Figure 6. The rotor 140 (e.g., made of fiber-filled plastic material) includes a central hub 141, which is mounted to the shaft 40 of the wheel assembly and is radially defined by a skirt portion 142. It also includes a plurality of blades 143 that extend radially from the skirt portion 142 to a belt 144. The belt 144 is circular and extends coaxially with the skirt portion 142 at the outer ends of the blades 143. Thus, the blades 143 are integral with the skirt portion 142 at their inner ends (i.e., the ends closest to the central axis XX) and with the belt 144 at their outer ends (i.e., the ends furthest from the central axis XX).

[0042] The belt 144 has an annular shape positioned at the outer end of the blade 143. It includes an inner surface 144a and an outer surface 144b, the inner surface contacting the blade 143 and the outer surface contacting the protective grille 120 and the ventilation element 170 as described below. The outer surface 144b is bluntly serrated and forms a labyrinth 145, which provides axial head loss. The labyrinth 145 is formed by a single blunt serration or several consecutive blunt serrations (e.g., from one blunt serration to five blunt serrations), which provide a barrier to airflow in a direction parallel to the central axis XX, so as to facilitate airflow between the skirt 142 and the inner surface 144a of the belt at the blade 143. By minimizing the air recirculation flow on the outer surface of the rotor 140, the belt 144 with its labyrinth 145 results in increased ventilation system performance while reducing noise levels.

[0043] The guard support 150 (an embodiment of which is shown in Figures 7 and 8) is formed of two distinct elements 160 and 170, which are attached to each other, for example, by a set of screws 151 shown in part B of Figures 7 and 8, or by an overmolding process. One of these elements (referred to as structural element 160) is designed as an integral part of the wheel assembly structure. For this purpose, structural element 160 is made of metal and includes an inner ring 161, an outer ring 162, and a plurality of arms 163 connecting the inner ring to the outer ring. The inner ring 161 has a circumferential shape adapted to allow the structural element to be inserted into the rim 20 of the wheel assembly. This circumferential shape may be the same as that provided for insertion into the rim of a prior art guard support. The outer ring 162 has a flat ring shape with an inner diameter larger than the outer diameter of the inner ring 161. Several arms 163, integral with the two inner rings 161 and the outer ring 162, are distributed on the circumference of the rings to ensure a certain rigidity of the structure while limiting its mass. The arm and ring can be manufactured as a single piece; conversely, they can be manufactured separately and secured to each other by welding, brazing, or any other known means for attaching metal parts. The inner ring 161 and outer ring 162, as well as the arm 163, have a circular profile (or outer line) without ridges to allow for optimal airflow circulation and, consequently, improve ventilation of the structural element 160. In other words, the shapes and dimensions of the inner ring 161, outer ring 162, and arm 163 are designed to limit losses and optimize airflow into the rotor 140.

[0044] The venting element 170 of the shield support 150 is a flat, crown-shaped element that receives the rotor 140 and directs airflow toward the wheel. For this purpose, the venting element 170 includes a first surface 171 and a second surface 172, the first surface contacting the structural element 160 and the second surface facing the protective grille 120. The second surface 172 may include a zigzag surface with cavities and blunt serrations to ensure a gain in mass. The first surface 171 includes a substantially flat surface adapted to connect to the outer ring 162 of the structural element 160, providing continuity between these surfaces in contact with air to ensure airflow guidance and limit losses. Furthermore, the venting element 170 includes a flanged edge 173 at its center, adapted to interlock the rotor's belt 144. This flanged edge 173 may be partially interlocked around the belt 144, for example, up to the first blunt serrations of the labyrinth 145. "Interlocking" means that the flanged edge 173 surrounds a portion of the belt 144, that is, the edge of the flange precisely wraps around the circumference of the belt 144 over a predetermined width of the belt, for example from the end of the belt to the first blunt serration of the labyrinth 145.

[0045] Since the ventilator element 170 does not have a structural function, it can be made of plastic (e.g., fibrous or non-fibrous PEEK (polyetheretherketone)) or resin, such as amorphous thermoplastic polyetherimide (e.g., ... Manufacturing process. In fact, plastics and resins have the advantages of being lighter and easier to mold than metals. Therefore, not only is the housing support 150, partially made of plastic or resin, lighter than prior art shield supports, but it also improves cooling by directing airflow toward the rotor 140. Furthermore, the venting element, made of plastic or resin, allows for optimization of the gap between the flanged edge 173 and the belt 144, enabling adjustment of the interlocking of the venting element 170 on the rotor 140, and thus avoiding noise caused by operating clearances.

[0046] Furthermore, manufacturing the shield support 150 as two separate components offers additional advantages: in the event of a severe impact, the ventilation element 170 and the rotor 140 can come into contact with each other without risk of damage. When both components are made of plastic or resin, the risk of rotor damage is lower than the risk of the rotor colliding with the metal shield support in current ventilation systems. Moreover, during aircraft maintenance, only one of the two components can be replaced, thus limiting maintenance costs.

[0047] In some embodiments, such as those shown in Figures 7 and 8, the outer rings 162 of the venting element 170 and the structural element 160 may each include radial openings 152 facing each other to allow, for example, a cable for checking tire pressure to pass through, with the edges 152a, 152b of the openings of the outer rings 162 connected by pins 153.

[0048] As shown in Figures 5 and 6, the rotor 140 is housed between the housing support 150 and the protective grille 120, as just described. An embodiment of the protective grille 120 is shown in the side view (Figure A) and front view (Figure B) of Figure 9. The protective grille comprises a housing 121 made of sheet metal, the housing having a first set of ports 122 and a second set of ports 123. The housing 121 has a generally bowl-shaped shape, having a circular bottom 121a extending in a radial plane and an edge 121b extending axially along the circumference of the bottom 121a.

[0049] The edge 121b of the housing 121 includes a substantially planar outer surface, i.e., without roughness, to optimize airflow through the protective grille 120. Furthermore, it includes an inner surface extending circumferentially towards the rotor 140 via a labyrinth 145. This inner surface of the edge 121b may include one or more blunt serrations complementary to one or more blunt serrations of the outer surface 144b of the band 144, such that they together form a barrier to airflow. Impeding the circulation of airflow between the rotor 140 and the protective grille 120 outside the rotor 140 not only optimizes airflow within the rotor but also reduces the noise level generated by airflow circulation.

[0050] The bottom 121a of the housing 121 is provided with a first set of ports 122 and a second set of ports 123. The ports in the first set of ports 122 face the rotor blades 143 and are adapted to allow airflow. These ports are as large as possible to allow the maximum amount of air to pass through. For example, each port in the first set of ports 122 may be substantially square in shape. The spacers between two consecutive ports are chosen to be as thin as possible to limit the noise level generated by the airflow above these spacers. In fact, the more discrete the spacers, the less obstruction to airflow, and therefore the less noise generated by the airflow.

[0051] The ports 123 of the second set of ports are accommodated in the central region of the bottom 121a and are adapted to reduce the mass of the protective grille. For example, these ports 123, positioned facing the central hub 141 of the rotor 140, may have an elongated elliptical shape to accommodate the maximum number of ports and, thus, to limit the mass of the protective grille to the greatest extent.

[0052] The dimensions of the ports and the space between them are determined based on the thickness of the metal plate forming the housing 121. To minimize the mass of the ventilation system, the metal plate of the housing 121 is chosen to be as thin as possible, for example, 2.5 mm thick. For very thin plates, such as 2.5 mm, reinforcements 124 between ports 122 of the first set of ports and ports 123 of the second set of ports can be uniformly provided on the circumference of the area of ​​the housing including the ports. These reinforcements 124 ensure the strength of the protective grille 120 to allow the shaft 40 to be held within its central region 125.

[0053] The protective grille 120 includes a raised edge 126 extending axially along the venting element 170 of the housing support on its circumference. This raised edge 126 forms a partial ring around the housing 121 for receiving attachment means for attaching the protective grille to the housing support. For example, these attachment means may include a plurality of holes 128 adapted to receive attachment screws and / or pins. For example, a central port 128a may be adapted to receive a pin 165 of the housing support 150, and these eccentric ports 128b may be adapted to receive attachment screws or bolts 166.

[0054] According to some embodiments, the ventilation system includes a right-angle rotary locking device 180 for attaching the protective grille 120 to the venting element 170 of the cover support. Figure 10 shows embodiments of the right-angle rotary locking device in an unlocked position (Figure A) and a locked position (Figure B). The right-angle rotary locking device 180 (more simply referred to as a locking device) includes a slot 181 formed on a second surface 172 of the venting element 170 and a tongue 182 formed on a raised edge 126 of the protective grille 120, the tongue 182 being interlockable into the slot 181. The locking device 180 may also include one or more sets of pins 183 and elongated elliptical ports 184 distributed on the circumference of the protective grille 120 and the venting element 170 to facilitate mounting of the protective grille 120 against the venting element 170. In this alternative, pin 183 can protrude from ventilator 170 or structural element 160 via a hole in the ventilator, and the pin of locking device 180 can then be pin 165 as previously described. This right-angle turn locking device 180 makes it possible to lock or unlock the protective grille by simple rotation. One or two screws or bolts 166 can supplement locking device 180 and are installed via the protective grille 120, ventilator 170, and structural element 160 for safety reasons, especially due to vibrations experienced by the ventilation system. Even with one or two screws or bolts 185, this protective grille 120 is easier to assemble and disassemble than prior art protective grilles, which require tightening / loosening nine bolts. This implementation of the protective grille allows for significant time savings during assembly or disassembly of the protective grille (e.g., during maintenance phases) and limits the risk of losing screws and / or bolts.

[0055] Figure 11 illustrates an embodiment of the airflow curves supplied to the wheel assembly by a ventilation system according to the prior art and the invention. These curves are represented in a reference frame, where the horizontal axis corresponds to the airflow through the ventilation system, and the horizontal axis corresponds to the pressure rise generated by the ventilation system. Curves C3 and C4 respectively show the actual performance of older and newer generation single-aisle aircraft. Curve C5 shows the air requirements of these aircraft. Curve C1 shows the pressure rise of the ventilation system according to the prior art. Curve C2 shows the pressure rise of the ventilation system according to the invention. The intersection of curve C2 with C3 or C4 indicates that the ventilation system according to the invention allows airflows of approximately 110 liters and 140 liters respectively, which is higher than the 100-liter air requirement of these aircraft (curve C5). Therefore, the ventilation system of the invention can be installed on any single-aisle aircraft. Thus, a ventilation system that reduces the inherent noise level to approximately 85 dB (which corresponds to approximately 80 dB at the aircraft periphery) provides sufficient airflow for the aircraft's needs without increasing its mass.

[0056] Although described by way of various embodiments, alternatives and implementations, the ventilation system for the aircraft wheel according to the invention includes various alternatives, modifications and improvements that will be obvious to those skilled in the art, and it should be understood that such alternatives, modifications and improvements are within the scope of the invention.

Claims

1. A ventilation system (100) for mounting along a central axis (XX) in an aircraft wheel and comprising a rotor (140), the rotor being fitted with a plurality of blades (143) and housed between a shield support (150) and a protective grille (120), the shield support and the protective grille being mounted along the central axis to each side of the rotor, the shield support being located inside the wheel. Its features are, The shield support (150) includes a structural element (160) juxtaposed with a venting element (170), the structural element (160) being made of metal and adapted to interlock with the wheel and support the rotor (140), the venting element (170) including a flat crown shape having a flanged edge (173) at its center, the flanged edge being at least partially adapted to a band (144) of the rotor (140), the venting element (170) being made of plastic or resin and adapted to direct airflow toward the rotor (140).

2. The ventilation system according to claim 1, characterized in that, The belt (144) of the rotor (140) extends circularly at the radial end of the blade (143) and includes a blunt serrated surface (145) capable of obstructing the flow of air, the blunt serrated surface including at least one blunt serration.

3. The ventilation system according to claim 1 or 2, characterized in that, The structural elements (160) of the protective cover support and the ventilation elements (170) are integrated together.

4. The ventilation system according to claim 1 or 2, characterized in that, The structural element (160) includes an inner ring (161), an outer ring (162), and a plurality of arms (163) distributed on the circumference of the inner ring and connecting the inner ring to the outer ring. The inner ring (161), the outer ring (162), and the arms (163) include a circular profile without ridges.

5. The ventilation system according to claim 4, characterized in that: The ventilation element (170) includes a first substantially flat surface (171) that can engage with the outer ring (162) of the structural element.

6. The ventilation system according to claim 1 or 2, characterized in that, The protective grille (120) includes a housing (121) having a first set of ports (122) and a second set of ports (123), the first set of ports (122) facing the rotor blades and adapted to allow airflow, and the second set of ports (123) facing the rotor hub (141) and adapted to reduce the mass of the protective grille.

7. The ventilation system according to claim 6, characterized in that, The protective grille (120) includes a raised edge (126) that extends axially at the outer end of the housing (121) and includes attachment means for attaching the protective grille (120) to the cover support (150).

8. The ventilation system according to claim 7, characterized in that, The ventilation system includes a right-angle slewing locking device (180) mounted to a protective grille (120) and a ventilation element (170) for attaching the protective grille to the ventilation element of the cover support.

9. A wheel assembly (10), comprising: - The wheel is mounted to the rim (20) and positioned around the central axis (XX). - A device (50) for braking the wheel, and - A ventilation system (100), arranged along the central axis, is used to cool the braking device by circulating airflow. The ventilation system (100) is characterized by being a ventilation system according to any one of claims 1 to 8.

10. The wheel assembly according to claim 9, characterized in that, The structural element (160) of the protective cover support is integrated with the wheel rim (20).

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