Heat shield and associated braking device

Abstract

Heat shield for a braking device of at least one aircraft wheel, the heat shield being intended to be arranged between an actuator support and a torque tube of said braking device, the heat shield comprising a plate (15) made of a thermally insulating material, the plate comprising a plurality of openings (18) extending transversely between two main faces of the plate, the heat shield comprising at least one insert (20) arranged at least partly inside one of the openings, the insert being made of a more rigid material than that of the plate. Associated braking device. FIGURE OF THE ABSTRACT: Fig. 2a

Description

Title of the invention: Heat shield and associated braking device

[0001] The invention relates to a heat shield for a braking device of at least one aircraft wheel.

[0002] The invention also relates to a braking device for at least one aircraft wheel comprising such a heat shield.

[0003] BACKGROUND OF THE INVENTION

[0004] An aircraft wheel is generally equipped with a braking device comprising rotor discs, integral in rotation with the wheel, and stator discs, immobilized in rotation with respect to the wheel, the rotor discs and stators being stacked alternately on a torque tube and thus forming a stack of discs.

[0005] The device further comprises an actuator support, generally called a crown, fixed to one end of the torque tube by means of screws. The crown has cavities in which are arranged braking actuators each equipped with a sliding piston. In addition, the crown comprises channels for circulating a pressurized hydraulic fluid to push the different pistons and thus exert a general force on the stack of discs.

[0006] The friction of the discs therefore makes it possible to produce a braking force. The stack of discs is therefore sometimes called a heat sink because it thermally dissipates the kinetic energy of the wheel during braking.

[0007] Consequently, during braking, the friction of the discs causes significant heating of the device. While the materials used for the various elements of the device generally resist this heating well, this is not the case for the hydraulic fluid present in the crown and the actuators. Indeed, under the effect of the heat released, the hydraulic fluid sees its efficiency deteriorate and its service life reduced. This therefore requires changing the hydraulic fluid relatively frequently, thereby increasing the time the aircraft is immobilized on the ground.

[0008] The problem described above is all the more present since the current strategy of air carriers consists of increasing the number of landings before overhaul (in English we speak of LPO for "Landing Per Overhaul") as well as the load capacity of aircraft. However, to increase the load capacity of aircraft, it is necessary to increase the mass of the heat sinks and consequently to increase the heating produced during the braking effort which deteriorates the quality of the hydraulic fluid even more quickly.

[0009] To limit the thermal exchanges between the stack of discs and the crown and thus To better protect the hydraulic fluid, a common approach is to interpose a heat shield made of thermally insulating material between the torque tube and the crown.

[0010] In order to further limit the heat exchanges between the stack of discs and the crown, it was envisaged by the present applicant to interpose, in addition to the aforementioned main heat shield, a secondary heat shield also made of thermally insulating material between the main heat shield and the torque tube.

[0011] It was envisaged that the secondary heat shield would be made of phenolic resin which is a good thermal insulator while allowing the secondary heat shield to be of low mass. Unfortunately, the secondary heat shield then tends to deform very quickly as it is used.

[0012] SUBJECT OF THE INVENTION

[0013] An aim of the invention is to propose a secondary heat shield which deforms less easily.

[0014] An aim of the invention is to propose a braking device which comprises such a heat shield. Summary of the invention

[0015] With a view to achieving this aim, a heat shield is proposed for a braking device of at least one aircraft wheel, the heat shield being intended to be arranged between an actuator support and a torque tube of said braking device, the heat shield comprising a plate made of a thermally insulating material, the plate comprising a plurality of openings extending transversely between two main faces of the plate.

[0016] According to the invention, the thermal screen comprises at least one insert arranged at least partly inside one of the openings, the insert being made of a more rigid material than that of the plate.

[0017] In this way, the heat shield incorporates at least one of its openings an insert which reinforces said opening. In particular, the insert improves the compression resistance of said opening.

[0018] This is particularly advantageous because the openings are the areas of the heat shield most subject to local deformation.

[0019] Thus, the risk of deformation of the heat shield is simply reduced while being able to choose a material with good thermally insulating properties for the plate (even if said material has less interesting mechanical rigidity properties than those of other materials).

[0020] Of course, the plate is made of a material with better thermal insulation characteristics than those of the insert material. The plate and the insert are therefore in different materials.

[0021] Optionally the insert is entirely arranged inside the opening.

[0022] Optionally, the heat shield further comprises at least one layer of thermally insulating material arranged in the opening so as to at least partially cover at least one of the faces of the insert.

[0023] Optionally, the layer of thermally insulating material is formed directly by an extension of the plate.

[0024] Optionally, the layer of thermally insulating material is a piece of thermally insulating material arranged in the opening.

[0025] Optionally at least one of the faces of the insert extends in the same plane as one of the faces of the plate.

[0026] Optionally the insert has a thickness identical to that of the opening.

[0027] Optionally the insert is shaped into a washer.

[0028] Optionally the insert is made of metal.

[0029] Optionally the plate is made of phenolic resin.

[0030] The invention also relates to a braking device for at least one aircraft wheel comprising such a heat shield.

[0031] Other characteristics and advantages of the invention will emerge from reading the following description of particular non-limiting embodiments of the invention. Brief description of the drawings

[0032] The invention will be better understood in light of the description which follows with reference to the appended figures among which:

[0033] [Fig-1] [Fig.l] is a sectional view of a part of the braking device of a aircraft wheel according to a first particular embodiment of the invention,

[0034] [Fig.2a] [Fig.2a] is a perspective view of a heat shield of the device illustrated in [Fig.l],

[0035] [Fig.2b] [Fig.2b] is an enlarged view of a portion of the heat shield illustrated in [Fig.2a],

[0036] [Fig.2c] [Fig.2c] is a schematic sectional view of the portion illustrated in [Fig.2b],

[0037] [Fig.3a] [Fig.3a] is a perspective view of a portion of a heat shield of a braking device of an aircraft wheel according to a second particular embodiment of the invention,

[0038] [Fig.3b] [Fig.3b] is a schematic sectional view of the portion illustrated in [Fig.3a],

[0039] [Fig.4a] [Fig.4a] is a perspective view of a portion of a heat shield of a braking device of an aircraft wheel according to a third embodiment particular of the invention,

[0040] [Fig.4b] [Fig.4b] is a schematic sectional view of the portion illustrated in [Fig.4a], DETAILED DESCRIPTION OF THE INVENTION

[0041] [Fig.l] illustrates a braking device, generally designated 1, of an aircraft wheel (not shown) according to a first particular embodiment of the invention.

[0042] In a manner known per se, the braking device 1 comprises a heat sink in the form of a stack of discs 9 composed of rotor discs 9a and stator discs 9b. The rotor discs 9a and stators 9b are stacked alternately on a torque tube 4 of the braking device. The wheel rotates here along an axis X of rotation, the torque tube 4 extending coaxially with said axis X.

[0043] The braking device 1 further comprises an actuator support, sometimes called a crown 5, fixed to one end of the torque tube 4 by means of screws 11 so as to also extend coaxially with the axis X. The crown 5 comprises a plurality of cavities 6 distributed regularly around the axis X and connected to each other by channels 7. Each of the cavities accommodates an actuator 8 capable of exerting a braking force on the disk stack 9 via a pressurized hydraulic fluid circulating inside the crown 5 through the channels 7. Each actuator 8 comprises a piston 10 sliding along a sliding axis parallel to the axis X. The piston 10 is composed of a head 12 for exerting pressure on a first stator disk 9b of the disk stack 9. The annular distribution of the actuators 8 makes it possible to distribute the braking force uniformly over the entire surface of the first stator disk 9b.

[0044] The braking device 1 is well known from the prior art and will not be detailed further in the present case.

[0045] The braking device 1 also generally comprises a first heat shield 13 interposed between the torque tube 4 and the crown 5 to protect said crown from the thermal radiation generated by the friction of the discs 9 during braking of the wheel.

[0046] The first heat shield 13 is for example formed from a piece of sheet metal, preferably in one piece. For example, the first heat shield 13 has a thickness of less than 1 millimeter. The first heat shield 13 is arranged in the device coaxially with the axis X. The first heat shield 13 has orifices regularly distributed around its circumference to receive the screws 11 ensuring the fixing of the crown 5 to the end of the torque tube 4.

[0047] Preferably, and as more visible in [Fig.2a], in order to reinforce the protection thermal shield of the crown 5 of the thermal conduction generated by the friction of the discs 9 during braking of the wheel, the braking device 1 comprises a second thermal shield 14 interposed between the first thermal shield 13 and the torque tube 4. The second thermal shield 14 is thus arranged in the device coaxially with the axis X.

[0048] Said second thermal screen 14 comprises a plate 15.

[0049] The plate 15 is generally annular in shape. The plate 15 thus has two main faces connected by an inner edge and an outer edge. The main faces 15 are here generally each shaped into a crown. More precisely here, the plate 15 has a base 16, shaped into a ring, base 16 from which a lug 17 extends radially. Apart from at the level of this lug 17, the plate 15 as a whole is shaped into a ring itself and its main faces are each shaped into a crown.

[0050] Preferably, the plate 15 is of a thickness greater than that of the first heat shield 13. Preferably, the plate 15 remains of small thickness. For example, the plate 15 has a thickness greater than 1 millimeter and less than 10 millimeters.

[0051] Said plate 15 is preferably formed from a single piece.

[0052] Preferably, said plate 15 is made of a material having good thermal insulation properties. For example, the plate 15 is made of a phenolic resin.

[0053] Apart from at its lug, the plate 15 has openings 18 regularly distributed around its circumference to receive the screws 11 ensuring the fixing of the crown 5 to the end of the torque tube 4. Indeed, at the lug 17, the plate 15 does not have an opening 18 formed in its base 16 (as on the rest of its circumference) but an orifice 19 formed at the junction between the lug 17 and the base 16, the orifice 19 allowing for example the passage of a sensor such as a thermal sensor such as for example a thermoprobe.

[0054] Said openings 18 (as well as the orifice 19) all extend so as to open out at the level of each of the two main faces of the plate 16.

[0055] The plate 16 preferably comprises between 8 and 15 openings and for example between 10 and 12 openings.

[0056] The second heat shield 14 being coaxial with the axis X, the different openings 18 and the orifice 19 of the plate 16 extend parallel to said axis X.

[0057] The various openings 18 and the orifice 19 here all have a circular section.

[0058] Furthermore, at least one of the openings 18 of the second heat shield 14 is provided with an insert 20 arranged at least partly inside said opening 18.

[0059] Of course, this insert 20 is pierced with a hole 21 to allow one of the screws 11 to pass through it (and therefore through the second heat shield 14). The insert 20 and its associated opening 21 extend coaxially to each other. In addition, the insert 20 (in place in the associated opening 18) extends parallel to the X axis.

[0060] Preferably, all the openings 18 of the second heat shield 14 are provided with an insert 20 arranged at least partly inside the associated opening 18 (a single insert being referenced in [Fig.2a]). In the present case, the different inserts 20 are identical to each other so that the following description of one of the inserts 20 is also applicable to the other inserts 20.

[0061] When the two heat shields 13, 14 are pinched between the torque tube 4 and the crown 5, the forces exerted by the crown 5 on the second heat shield 14 are substantially uniformly distributed on a first of the two main faces of the second heat shield 14 because the crown 5 does not press directly on the second heat shield 14 but via the first heat shield 13. On the other hand, the forces exerted by the torque tube 4 on the second heat shield 14 are not as uniformly distributed because the torque tube 4 presses directly on the second heat shield 14 and only at the areas of the plate 15 incorporating the openings 18 (and possibly the orifice 19).This therefore generates significant stresses in the plate 15 at the level of the openings 18: the insert 20 cleverly makes it possible to locally stiffen the associated opening 18 to avoid deformation thereof due to the stresses undergone.

[0062] It is noted that this phenomenon is not as significant at the level of the orifice 19 of the second heat shield 14 so that this orifice 19 can be provided with an insert but can also not be provided with an insert.

[0063] The insert 20 is made of a more rigid material than that of the plate 15. The insert 20 is thus made of a material having a higher Young's Modulus than that of the plate 15.

[0064] The insert 20 preferably has a very high Young's modulus. The insert 20 is thus a rigid insert.

[0065] For example, the insert 20 has a Young's Modulus greater than 50 GigaPascal (GPa) and preferably greater than 60 GPa and preferably greater than 65 GPa. The insert 20 has, for example, a Young's Modulus of between 68 and 210 GPa.

[0066] For comparison, the plate 15 has a Young's Modulus preferably less than 10 GPa and preferably less than 5 GPa. For example, the plate 15 has a Young's Modulus of between 2.7 and 5 GPa.

[0067] For example, the insert 20 is made of or based on:

[0068] - of at least one metal and for example made of or based on titanium, copper, steel (such as stainless steel, etc.), brass, etc., and / or - of at least one polymer and for example made of or based on polyetheretherketone (better known by the acronym PEEK, registered trademark).

[0069] The insert 20 is for example shaped as a washer. The insert 20 thus has two main crown-shaped faces connected by a single internal edge and a single external edge.

[0070] In the first embodiment, as more visible in figures 2b and 2c, the insert 20 is shaped so as to have a thickness (thickness considered along the axis along which the insert 20 extends in the associated opening 18, i.e. an axis parallel to the axis X) equal to that of the plate 15.

[0071] The insert 20 thus extends into the associated opening 18 so that at least one of its main faces extends in the same plane as one of the main faces of the plate 15 and preferably so that each of its main faces extends in the same plane as a respective one of the main faces of the plate 15.

[0072] The insert 20 therefore does not protrude from the opening.

[0073] Thus it proves very simple to arrange the inserts 20 in the second heat shield 14 since it suffices to introduce each insert 20 into the associated opening 18 so that each insert 20 does not protrude from the plate 15.

[0074] At least one of the inserts 20 is for example forced into the associated opening 18 or even glued into the associated opening 18.

[0075] Alternatively, at least one of the inserts 20 is for example placed in a mold for manufacturing the plate 15 so as to be molded directly in the plate 15 during the manufacture of the latter.

[0076] In all cases, said insert 20 is thus very well secured to the plate 15. With reference to FIGS. 3a and 3b, a second embodiment will now be described.

[0077] This second embodiment is identical to the first embodiment except at the level of the inserts 20 and the corresponding openings 18 of the second thermal screen 14.

[0078] However, here again, at least one of the openings 18 of the second heat shield 14 is provided with an insert 20 arranged at least partly inside said opening 18.

[0079] Preferably, all the openings 18 of the second heat shield 14 are provided with an insert 20 arranged at least partly inside the associated opening 18. In the present case, the different inserts 20 are identical to each other so that the following description of one of the inserts 20 is also applicable to the other inserts 20.

[0080] Of course, this insert 20 is drilled to allow one of the screws 11 to pass through it (and therefore through the second heat shield 14). The insert 20 and its associated opening 18 extend coaxially to each other. Furthermore, the insert 20 (in place in the associated opening 18) extends parallel to the X axis.

[0081] The insert 20 is made of a more rigid material than that of the plate 15. The insert 20 is thus made of a material having a higher Young's Modulus than that of the plate 15.

[0082] The insert 20 preferably has a very high Young's modulus. The insert 20 is thus a rigid insert.

[0083] For example, the insert 20 has a Young's Modulus greater than 50 GigaPascal (GPa) and preferably greater than 60 GPa and preferably greater than 65 GPa. The insert 20 has, for example, a Young's Modulus of between 68 and 210 GPa.

[0084] For comparison, the plate 15 has a Young's Modulus preferably less than 10 GPa and preferably less than 5 GPa. For example, the plate 15 has a Young's Modulus of between 2.7 and 5 GPa.

[0085] For example, the insert 20 is made of or based on:

[0086] - of at least one metal and for example made of or based on titanium, copper, steel (such as stainless steel, etc.), brass, etc., and / or - at least one polymer and for example made of or based on polyetheretherketone (better known by the acronym PEEK, registered trademark).

[0087] The insert 20 is for example shaped as a washer. The insert 20 thus has two main crown-shaped faces connected by a single internal edge and a single external edge.

[0088] In this second embodiment, the insert 20 is shaped so as to have a thickness (thickness considered along the axis along which the insert 20 extends in the associated opening 18, i.e. an axis parallel to the axis X) less than that of the plate 15.

[0089] The insert 20 thus extends entirely inside the opening 18 without protruding beyond it.

[0090] In the present case, the insert 20 does not protrude from either of the two main faces of the platinum 15.

[0091] This allows for better thermal insulation between the torque tube 4 and the second heat shield 14 since the torque tube 4 does not (or only slightly) press on the insert 20 unlike in the first embodiment. Preferably, the plate 15 covers at least partially one of the main faces of the insert 20 when the latter is in place in the associated opening 18.

[0092] For example, the plate 15 covers at least partially each of the main faces of the insert 20 when the latter is in place in the associated opening 18.

[0093] For this purpose, whereas in the first embodiment, the diameter of the opening 18 was the same over the entire section of the opening 18, in the second embodiment, the diameter of the opening 18 is here different at its two ends opening onto the main faces of the plate 15.

[0094] On its central section (as in the first embodiment), the diameter of the opening 18 is similar (plus or minus 1%) or equal to the external diameter of the insert 20.

[0095] On the other hand, on its two end sections, the opening 18 has a diameter similar (plus or minus 1%) or equal to that of the central hole 21 of the insert 20 through which the screw 11 extends in service.

[0096] In this way, the insert 20 is included in the plate 15, at the level of the end sections of the opening 18 (of a diameter smaller than that of the central section of the opening 18).

[0097] The insert 20 is thus very well secured to the plate 15.

[0098] Advantageously, the main faces of the insert 20 are thus each covered with a thermally insulating layer 22 (i.e. layers formed directly by the plate 15) which further improves the thermal insulation between the torque tube 4 and the second thermal screen 14. In fact, the torque tube 4 presses directly on the thermally insulating layers 22 of the plate 15 covering the insert 20.

[0099] To arrange the insert in the plate 15, the insert 20 is for example placed in a mold for manufacturing the plate 15 so as to be molded directly in the plate 15 during the manufacture of the latter.

[0100] According to a variant of this second embodiment, for at least one of the main faces of at least one of the inserts 20, when the latter is in place in the associated opening 18, the plate 15 does not at least partially cover said main face. There is therefore a space left empty between said main face and the main face closest to the plate 15.

[0101] For example, at least one of the inserts is for example placed in a mold for manufacturing the plate 15 so as to be molded directly in the plate 15 during the manufacture of the latter.

[0102] Alternatively, at least one of the inserts 20 is forced into the associated opening 18 or even glued into the associated opening 18.

[0103] Said insert 20 is thus very well secured to the plate 15.

[0104] Whatever the variant envisaged, it is therefore understood that the second embodiment is identical to the first embodiment apart from the thickness of the inserts 20 and, possibly, apart from the diameter and the shape of the openings 18 of the plate 15. With reference to FIGS. 4a and 4b, a third embodiment will now be described.

[0105] This third embodiment is identical to the second embodiment except at the level of the inserts 20.

[0106] However, here again, at least one of the openings 18 of the second heat shield 14 is provided with an insert 20 arranged at least partly inside said opening. 18.

[0107] Preferably, all the openings 18 of the second heat shield 14 are provided with an insert 20 arranged at least partly inside the associated opening 18. In the present case, the different inserts 20 are identical to each other so that the following description of one of the inserts 20 is also applicable to the other inserts 20.

[0108] Of course, this insert 20 is drilled to allow one of the screws 11 to pass through it (and therefore through the second heat shield 14). The insert 20 and its associated opening 18 extend coaxially to each other. Furthermore, the insert 20 (in place in the associated opening) extends parallel to the X axis.

[0109] The insert 20 is made of a more rigid material than that of the plate 15. The insert 20 is thus made of a material having a higher Young's Modulus than that of the plate 15.

[0110] The insert 20 preferably has a very high Young's modulus. The insert 20 is thus a rigid insert 20.

[0111] For example, the insert 20 has a Young's Modulus greater than 50 GigaPascal (GPa) and preferably greater than 60 GPa and preferably greater than 65 GPa. The insert 20 has, for example, a Young's Modulus of between 68 and 210 GPa.

[0112] For comparison, the plate 15 has a Young's Modulus preferably less than 10 GPa and preferably less than 5 GPa. For example, the plate 15 has a Young's Modulus of between 2.7 and 5 GPa.

[0113] For example, the insert 20 is made of or based on:

[0114] - of at least one metal and for example made of or based on titanium, copper, steel (such as stainless steel, etc.), brass, etc., and / or - at least one polymer and for example made of or based on polyetheretherketone (better known by the acronym PEEK, registered trademark).

[0115] The insert 20 is for example shaped as a washer. The insert 20 thus has two main crown-shaped faces connected by a single internal edge and a single external edge.

[0116] In this third embodiment, the insert 20 is shaped so as to have a thickness (thickness considered along the axis along which the insert extends in the associated opening 18, i.e. an axis parallel to the axis X) less than that of the plate 15.

[0117] The insert 20 thus extends entirely inside the opening 18 without protruding beyond it.

[0118] In the present case, the insert 20 does not protrude from either of the two main faces of the platinum 15.

[0119] This allows for better thermal insulation between the torque tube 4 and the second thermal screen 14 since the torque tube 4 does not (or only slightly) press on the insert 20 unlike the first embodiment.

[0120] Preferably, the second thermal screen 14 comprises at least one part made of thermally insulating material covering at least partially one of the main faces of the insert 20 when the latter is in place in the associated opening 18.

[0121] For example, the second heat shield 14 comprises a first part 23 made of thermally insulating material covering at least partially the first main face of the insert 20 and a second part 24 made of thermally insulating material covering at least partially the second main face of the insert 20. The two parts 23, 24 being identical to each other, the following description of one of them (23) is also applicable to the other of them (24).

[0122] The part 23 is thus arranged at least partly inside the associated opening 18 (the insert 20 being here therefore arranged entirely in the opening 18 while being blocked on either side by the two associated parts 23, 24).

[0123] Of course, this part 23 is pierced with a hole 25 to allow the passage of one of the screws 11 through it and therefore through the second heat shield 14. Preferably, the part 23 is shaped so that its hole 25 has a diameter identical to that of the hole 21 of the insert 20.

[0124] The part 23 and its associated opening 18 extend coaxially to each other. Furthermore, the part 23 (in place in the associated opening 18) extends parallel to the X axis.

[0125] The part 23 is made of a thermally insulating material and for example phenolic resin. Of course, the part 23 is made of a material having better thermal insulation properties than the insert 20. The insert 20 and the part 23 are therefore made of different materials.

[0126] The part 23 is for example shaped like a washer. The part 23 thus has two main crown-shaped faces connected by a single internal edge and a single external edge.

[0127] Preferably, the part 23 is shaped so as to have a thickness (thickness considered along the axis along which the insert 20 extends in the associated opening 18, i.e. an axis parallel to the axis X) equal to the distance separating the main face of the insert 20 opposite said part 23 from the corresponding main face of the plate 15.

[0128] The part 23 thus extends into the opening 18 so that at least:

[0129] - one of its main faces extends in the same plane as one of the main faces of the plate 15, and / or - one of its main faces is attached to one of the main faces of the insert 20.

[0130] The part 23 preferably extends into the opening 18 so that its first face main face extends in the same plane as one of the main faces of the plate 15 and that its second main face is attached to one of the main faces of the insert 20.

[0131] In this way, the part 23 fills the space separating the main face of the insert 20 from the main face of the nearest plate 15.

[0132] The part 23 thus extends entirely inside the opening 18 without protruding beyond it.

[0133] In this way, the insert 20 is located in the plate 15 framed by the two parts.

[0134] Advantageously, the main faces of the insert 20 are thus each covered with a thermally insulating layer (i.e. layers formed by one of the parts 23, 24) which further improves the thermal insulation between the torque tube 4 and the second thermal screen 14. In fact, the torque tube 4 presses directly on the thermally insulating layers of the plate 15 covering the insert 20.

[0135] To arrange the insert 20 in the plate 15, the insert 20 is for example placed in a mold for manufacturing the plate 15 so as to be molded directly in the plate 15 during the manufacture of the latter. Alternatively, the insert 20 is forced into the associated opening 18 or even glued into the associated opening 18.

[0136] The insert 20 is thus very well secured to the plate 15.

[0137] Then the parts 23, 24 are in turn arranged in the opening 18 on either side of the insert 20. The parts 23, 24 are preferably secured to the insert 20 (for example by gluing) or are optionally simply attached to the insert 20 without being secured to it.

[0138] The parts 23, 24 can alternatively be secured to the insert 20 (for example by gluing) so that the assembly formed by the insert and the parts is introduced into the opening 18 in a single maneuver.

[0139] This makes it easy to ensure good thermal insulation between the torque tube 4 and the crown 5 even at the openings 18 of the second thermal screen 14.

[0140] It is therefore understood that the third embodiment is identical to the first embodiment apart from the thickness of the inserts 20 and the additional presence of the parts 23, 24.

[0141] Whatever the embodiment envisaged, the second thermal screen 14 makes it possible to reduce the thermal exchanges (in particular the thermal exchanges by conduction) between the crown 5 and the torque tube 4, which is heated by the heat sink, while presenting good physical integrity due to the presence of the inserts 20 in its openings 18.

[0142] Of course, the invention is not limited to the embodiments described and variations can be made without departing from the scope of the invention as defined by the res- instructions.

[0143] The braking device described may not include a first heat shield but only the second heat shield according to the invention.

[0144] Although here the plate is in a phenolic resin, the plate could be in another material and for example in or based on cork, in or based on ceramic (and for example the PyroSic brand product), in or based on a polymer such as a thermoplastic and for example the thermoplastic of the brand "polyetheretherketone" (better known by the acronym "PEEK"), ...

[0145] The plate may have a shape other than that described. For example, the plate may have a base without a tab and, for example, a base in a ring, without a tab. The plate may thus be shaped as a whole into a ring itself and its main faces each shaped into a crown.

[0146] Independently of the shape of the plate (and in particular independently of the presence of a tab or not), the plate may include, in addition to the openings for the passage of the screws, at least one orifice for the passage of a sensor and, for example, at least two orifices. As a replacement, independently of the shape of the plate (and in particular independently of the presence of a tab or not), the plate may only include openings regularly distributed around its circumference to receive the screws (and no orifice for the passage of a sensor).

[0147] Although in the second embodiment, the two main faces of the insert are covered by the plate, only one of the main faces of the insert may be covered at least partially by the plate. The other of the faces may, for example, extend in the same plane as one of the main faces of the plate (as in the first embodiment) or be associated with a part made of thermally insulating material (as in the third embodiment) or may extend inside the opening without an element to fill the space with the main face of the associated plate.

[0148] Although in the third embodiment, the two main faces of the insert are each covered with a piece of thermally insulating material, only one of the main faces of the insert may be covered at least partially by such a piece. The other of the faces may, for example, extend in the same plane as one of the main faces of the plate (as in the first embodiment) or may extend inside the opening without an element to fill the space with the main face of the associated plate.

[0149] Whatever the embodiment envisaged, it is possible to cover (at least partially) at least one of the main faces of the insert with a layer of thermally insulating material which is different from what has been indicated, such as for example a simple coating layer of thermally insulating material. Said This layer can be applied before the insert is fitted into the plate or once the insert is fitted into the plate. The thermally insulating material coating can be a layer of resin, paint, etc. Of course, several parts made of thermally insulating material can be associated with the same main face of the insert. The second thermal shield can include at least one other part (which is not necessarily made of a thermally insulating material), such as an adhesive washer to secure, for example, a part made of thermally insulating material to the insert.

[0150] A variant of the first embodiment may be envisaged in which the thickness of the insert is less than that of the associated opening without a layer of thermally insulating material (whatever it may be) filling the space between the main face of the plate and the main face of the corresponding insert.

[0151] At least one insert and / or one part may have a shape other than that described as a washer. For example, at least one insert and / or one part may be shaped so as to have an external edge having at least two external flanks (and not a single flank as in the various embodiments described) and for example a succession of external flanks. At least one insert and / or one part may thus be shaped externally into a nut. Preferably then, the associated opening will have a corresponding section (and not a circular section as in the various embodiments described) to facilitate the attachment of the insert and / or the part in the associated opening.

[0152] Alternatively or in addition, and whatever the shape of at least one insert (washer-shaped or not), the insert and / or the associated opening may be shaped to ensure that the insert is held in the associated opening. For example, the insert and / or the associated opening may include at least one textured area (area having at least one spike, at least one groove (partial or total), at least one rib (openwork or not openwork), at least one chevron, at least one rough appearance, at least one rough coating, etc. - the textured area may thus form a design comprising at least one straight line extending axially, at least one grid, at least one sinusoid, at least one triangular signal, at least one rectangular signal, at least one chevron, etc.) and / or having a surface treatment facilitating the attachment of the insert in the associated opening.Said zone may extend over the entire circumference of the outer edge of the insert or over only part of the outer edge of the insert and / or over the entire length (depending on the axial direction of the insert) of said outer edge or over only part of said outer edge. Alternatively or in addition and whatever the shape of at least one part (washer-shaped or not), the part and / or the associated opening may be shaped to ensure that the part is held in the associated opening. For example, the part and / or the associated opening may. include at least one textured area (area having at least one spike, at least one groove (partial or total), at least one rib (openwork or not openwork), at least one chevron, at least one rough appearance, at least one rough coating, etc. - the textured area may thus form a design comprising at least one straight line extending axially, at least one grid, at least one sinusoid, at least one triangular signal, at least one rectangular signal, at least one chevron, etc.) and / or having a surface treatment facilitating the attachment of the part in the associated opening. Said area may extend over the entire circumference of the external edge of the part or over only part of the external edge of the part and / or over the entire length (depending on the axial direction of the part) of said external edge or over only part of said external edge.

[0153] Alternatively or in addition, the second heat shield may include other means for attaching the part and / or the insert to the associated opening, such as, for example, a layer of glue.

Claims

Claims

1. Heat shield for a braking device of at least one aircraft wheel, the heat shield being intended to be arranged between an actuator support and a torque tube of said braking device, the heat shield comprising a plate (15) made of a thermally insulating material, the plate comprising at least one opening (18) extending transversely between two main faces of the plate, the heat shield being characterized in that it comprises at least one insert (20) arranged at least partly inside the opening, the insert being made of a more rigid material than that of the plate.

2. A heat shield according to claim 1, wherein the insert (20) is entirely arranged within the opening (18).

3. Thermal screen according to one of claims 1 to 2, further comprising at least one layer of thermally insulating material arranged in the opening (18) so as to at least partially cover at least one of the faces of the insert (20).

4. Heat shield according to claim 3, in which the layer of thermally insulating material is formed directly by an extension (22) of the plate.

5. A heat shield according to claim 3, wherein the layer of thermally insulating material is a piece (23, 24) of thermally insulating material arranged in the opening.

6. Heat shield according to one of the preceding claims, in which at least one of the faces of the insert (20) extends in the same plane as one of the faces of the plate (15).

7. A heat shield according to claim 6, wherein the insert (20) has a thickness identical to that of the opening (18).

8. Heat shield according to one of the preceding claims, in which the insert (20) is shaped as a washer.

9. Heat shield according to one of the preceding claims, in which the plate (15) is made of phenolic resin.

10. Braking device for at least one aircraft wheel comprising a heat shield according to one of the preceding claims.

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