Brake disc, particularly for aircraft, comprising carbon reinforcement pads, and method for manufacturing such pads.

Abstract

Brake disc (10, 40), comprising an annular disc (12) made of carbon / carbon composite material having a radially external periphery (12A) and a radially internal periphery (12B), a plurality of notches (14) being provided on the radially external periphery (12A) or on the radially internal periphery (12B), each notch (14) being provided with a pair of reinforcing pads (16) made of carbon / carbon composite material arranged opposite each other in the circumferential direction (C), each reinforcing pad (16) having a flat contact surface (16A) configured to cooperate with the torque-absorbing element (50, 52), the annular disc (12) having a compression modulus that is maximum in the axial direction (X) while each reinforcing pad (16) has a compression modulus that is maximum in a direction (E) perpendicular to the contact surface (16A). Figure for the abstract: Fig. 1.

Description

Title of the invention: Brake disc, in particular for aircraft, comprising carbon reinforcement pads, and method of manufacturing such pads. technical field

[0001] The present description relates to a brake disc, for example for aircraft brakes (or aircraft landing gear brakes), comprising carbon reinforcement pads, and a method for manufacturing such pads. The brake disc may be a stator disc or a rotor disc. Previous technique

[0002] Known aircraft brake discs generally have metal reinforcements on the side walls of the slots that receive the torque-retaining elements. These reinforcements cooperate directly with the torque-retaining elements to protect the annular carbon / carbon composite disc of the brake disc. However, these metal reinforcements can deteriorate prematurely while the disc has not yet reached its normal wear limit, resulting in maintenance or premature disc replacement. Such premature replacement is particularly detrimental from both a financial standpoint, as these discs are especially expensive, and an environmental one, as carbon / carbon composite materials are highly polluting, notably due to the significant amount of non-recyclable waste generated during their manufacture.Therefore, there is a need to improve the reliability of brake discs with a carbon / carbon composite warp. Description of the invention

[0003] One embodiment relates to a brake disc, for example for an aircraft brake, comprising an annular disc made of carbon / carbon composite material extending in a radial direction, an axial direction, and a circumferential direction, the annular disc having a radially external periphery and a radially internal periphery, a plurality of notches being provided on the radially external periphery or on the radially internal periphery of the annular disc, each notch being through-hole in the axial direction, each notch being provided with a pair of reinforcing pads made of carbon / carbon composite material arranged opposite each other in the circumferential direction, an axial groove being provided between each pair of pads, the axial groove being configured to receive a torque-absorbing element, each reinforcing pad having a flat contact surface configured to cooperate with the torque-absorbing element, the disc annular exhibiting a compression modulus that is maximum along the axial direction while each reinforcing pad exhibits a compression modulus that is maximum along a direction perpendicular to the contact surface.

[0004] Hereafter and unless otherwise indicated, "disc" means "brake disc", "veil" means "annular veil", "pad" means "reinforcing pad", and "groove" means "axial groove".

[0005] Generally, the axial direction corresponds to the direction of the axis of the web (or disk), and the radial direction is a direction perpendicular to the axial direction. The circumferential (or azimuthal) direction corresponds to the direction describing a ring around the axial direction. The three directions axial, radial, and circumferential correspond respectively to the directions defined by the rib, the radius, and the angle in a cylindrical coordinate system. Finally, unless otherwise specified, the adjectives "inside" and "outside" are used with reference to a radial direction such that the inner (i.e., radially inner) part of an element is closer to the axis of the web than the outer (i.e., radially outer) part of the same element.

[0006] The annular disc, or radial annular disc, has a greater radial extent than its axial extent. On each of its two opposite sides along the axial direction, the annular disc has a wear track, which is the portion configured to cooperate in friction with another disc of a different brake disc, e.g., the wear track of another disc of a different brake disc. Each wear track extends radially over at least a portion of the disc between its inner and outer peripheries.

[0007] The notches of the plurality of notches each form a groove that opens radially inward if they are formed on the radially inner periphery of the web, or outward if they are formed on the radially outer periphery of the web, and extend parallel to the axial direction, so as to pass completely through the web along the axial direction. For example, if the notches are formed on the radially outer periphery of the web, the disk can be a rotor disk, configured to be coupled to a wheel, for example, a wheel of an aircraft landing gear. For example, if the notches are formed on the radially inner periphery of the web, the disk can be a stator disk, configured to be coupled to a stationary rotating part of an aircraft landing gear brake, such a part being known, for example, to those skilled in the art as a "torque tube".

[0008] A person skilled in the art sometimes refers to the notches using the term "tenon," for example, "internal tenon" for notches made on the radially internal periphery or "external tenon" for notches made on the periphery radially external. The portion of the radially internal or external periphery that extends between two adjacent notches of the same periphery is sometimes referred to by those skilled in the art as the "free edge". Torque-bearing elements may be known to those skilled in the art as "torque bar" for torque-bearing elements connected to the wheel, or as "rail" or "spline" for torque-bearing elements connected to the brake, e.g., connected to the torque-bearing tube of a brake.

[0009] Two pads are arranged opposite each other in the circumferential direction within each notch. In other words, each pad can cover all or part of a lateral wall of a notch, i.e. a wall extending in the radial direction and in the axial direction.

[0010] Within the same notch, the contact surface of one pad of the pair of pads is opposite the contact surface of the other pad of the pair of pads. For example, the contact surface of each pad may extend over the entire radial and axial extent of the notch in which said reinforcing pad is housed.

[0011] The lateral walls of the groove, i.e. the walls extending in the radial direction and in the axial direction, can be formed by the contact surfaces of the pads, while the bottom of the groove, e.g. a surface extending in the circumferential direction and in the axial direction, can be formed by the web.

[0012] A carbon / carbon composite material is a composite material where the matrix is ​​carbon-based and the fibers are carbon fibers.

[0013] Depending on the orientation of the carbon fibers within the material, certain material characteristics can be adjusted anisotropically. For example, if a greater quantity of carbon fibers is oriented in a predetermined direction compared to carbon fibers oriented in other directions, the material may exhibit a higher compressive modulus in this predetermined direction compared to the compressive moduli of the same material in other directions. The compressive modulus in this predetermined direction can thus be a maximum compressive modulus of the material.

[0014] For a carbon / carbon composite material, resistance to wear due to friction is related to the compressive modulus. Therefore, when a compressive modulus is maximum along a predetermined direction, a surface of the material extending perpendicularly to this predetermined direction exhibits particularly high resistance to wear due to friction along this surface, perpendicular to the predetermined direction.

[0015] Also, the annular disc, having a compression modulus that is maximum along the axial direction (i.e., perpendicular to the disc's braking surface), is particularly resistant to wear induced by braking friction, for example, between the different stator / rotor discs within an aircraft brake. On the other hand, the disc is less resistant, particularly to compression / punching, at the slots that are subjected to mechanical stresses, via the torque-response elements, during torque transfer during braking. This is why the slots of prior art discs are generally fitted with metal pads, as metal is particularly resistant to compression / punching stresses compared to the carbon / carbon composite material of the disc.

[0016] However, the inventors have identified that the interfaces between the disc and the torque-absorbing elements are subjected to particularly high friction, not only during braking (during the axial translation of the disc along the torque-absorbing elements), but also due to vibrations induced under other conditions, such as during aircraft taxiing on the ground. The inventors have thus identified one of the reasons for the premature wear of the prior art metal brake pads.

[0017] By orienting the carbon / carbon composite pads so that the compression modulus is maximized in a direction perpendicular to the contact surface, these pads are made particularly resistant not only to the mechanical stresses absorbed by the torque elements during braking, but also to wear induced by friction with the torque elements. Furthermore, since the torque elements are generally made of metal, the coefficient of friction between the torque elements and the carbon / carbon composite pads is more favorable than the coefficient of friction with prior art metal pads. This reduces friction at the interface and the resulting wear. As the discs slide along the torque elements during braking, brake efficiency is also improved.

[0018] Furthermore, since the pads are made of carbon / carbon composite material, any portion of the pads extending onto the brake track of the disc can follow the disc's wear throughout its lifespan without any detrimental interference. This improves the reliability and lifespan of the brake disc. In addition, because the pads and the disc are made of the same material, their coefficient of thermal expansion is very similar or identical, which enhances the reliability of assembling such pads with such a disc.

[0019] Such skates made of carbon / carbon composite material whose compression modulus is maximum in a direction perpendicular to the contact surface This allows the sail to be preserved satisfactorily while offering improved reliability compared to state-of-the-art metal pads.

[0020] In certain embodiments, the contact surface of each reinforcing pad extends radially beyond the periphery where the notch housing said reinforcing pad is provided, opposite the bottom of the axial groove, and / or extends radially below the bottom of the axial groove within the annular web, opposite said periphery.

[0021] In other words, the contact surface, and therefore the corresponding portion of the pad, can extend radially beyond the circumferential edge of the web forming the periphery where the notch is provided, i.e. the contact surface can extend radially outwards beyond the outer periphery if the notches are provided in the outer periphery or the contact surface can extend radially inwards beyond the inner periphery if the notches are provided in the inner periphery.

[0022] In addition or as an alternative, the contact surface, and therefore the corresponding portion of the pad, can extend radially below the bottom of the groove, i.e. the contact surface can extend radially inwards below the bottom of the groove if the notches are provided in the outer periphery or the contact surface can extend radially outwards below the bottom of the groove if the notches are provided in the inner periphery.

[0023] Such a configuration can maximize the dimensions of the contact surface, thereby improving the distribution of forces induced by torque transfer via the torque transfer elements during braking, and thus reducing local stresses within the disc. Such a configuration can help preserve the disc and improve its reliability.

[0024] In certain embodiments, each reinforcing pad cooperates by complementarity of form with a radial wall and a portion of the bottom wall of the notch in which said reinforcing pad is housed, so as to radially and circumferentially lock the reinforcing pad within said notch when reinforcing pad is subjected to a circumferential force pushing the reinforcing pad against said radial wall.

[0025] The notch may have a portion configured to receive the pad and cooperate with the pad by complementary shape, such that when the pad interacts with the torque-absorbing element, the resulting force tends to clamp the pad within the notch. This can, on the one hand, help to better distribute the forces exerted on the pad within the disc, and thus reduce local stresses within the disc, and on the other hand, ensure a self-locking of the pad within the notch when the pad interacts with the torque-absorbing element. Such a configuration can help to preserve the disc and improve its reliability.

[0026] In certain embodiments, each notch has, considered along the axial direction, two V-shaped portions, the opening of the V of each V-shaped portion opening into the notch and being arranged opposite each other, each V-shaped portion receiving a reinforcing pad and cooperating by complementarity of form with said reinforcing pad.

[0027] The interior of the "V" shapes forms a portion of the notch (i.e., the interior of the "V" is empty). The web (i.e., the material) forms the exterior of the "V" shape. For example, each "V"-shaped portion of the notch can be delimited by a radial wall and a portion of the bottom wall of the notch, each of these walls forming, for example, a branch of the "V".

[0028] For the purposes of this exposition, the two "V" shapes are considered in relation to each other insofar as, considered along the axial direction, at least a portion of the opening of the "V" of one "V" shaped portion is opposite, for example along the circumferential direction, with at least a portion of the opening of the "V" of the other "V" shaped portion.

[0029] Such "V" shapes can ensure self-locking of the pad within the notch when the pad engages with the torque-retaining element, while also allowing for easy mounting of the pad within the "V" shape, for example by sliding or interlocking along the axial direction. Such a configuration can help preserve the runout and improve the reliability of the disc.

[0030] In certain embodiments, the two branches of the "V" of each "V"-shaped portion form an angle between 70° (seventy degrees angle) and 100° (one hundred degrees angle), one branch of the "V" of each "V"-shaped portion forming an angle between 10° (ten degrees angle) and 30° (thirty degrees angle) with the radial direction.

[0031] For example, for a stator disk, the two branches of the "V" of each "V"-shaped portion can form an angle between 70° (seventy degrees of angle) and 100° (one hundred degrees of angle) while for a rotor disk the two branches of the "V" of each "V"-shaped portion form an angle between 80° (eighty degrees of angle) and 100° (one hundred degrees of angle).

[0032] The arm of the "V" forming an angle between 10° and 30° with the radial direction, which may be formed by a radial wall of the notch, is inclined with respect to the radial direction towards the inside of the notch so that, in the circumferential direction, the distal ends of the arms of the "V" are closer than the proximal ends of said arms of the "V". Considered in the axial direction, the arms forming an angle between 10° and 30° with the radial direction of the two "V"-shaped portions within the same notch are the opposite arms furthest outside the notch in the circumferential direction. In other words, with the "V"-shaped portions facing each other, the angle formed with the radial direction of one "V"-shaped portion is oriented opposite to the angle formed with the radial direction of the other "V"-shaped portion.

[0033] Such a configuration can ensure that the pad is locked in place and that the forces are distributed favorably within the disc. This can help to preserve the disc and improve its reliability.

[0034] In certain embodiments, the contact surfaces of the two reinforcing pads of each pair of reinforcing pads together form, considered along the axial direction, a truncated "V" shape, the opening angle of the truncated "V" being between 0° (zero degree angle) and 25° (twenty-five degree angle).

[0035] For example, for a stator disk the opening angle of the truncated "V" can be between 0° (zero degree angle) and 25° (twenty-five degree angle) while for a rotor disk the opening angle of the truncated "V" can be between 5° (five degree angle) and 25° (twenty-five degree angle)

[0036] The truncated "V" has an opening oriented towards the radial periphery in which the notch is formed, namely outwards if the notch is formed in the outer radial periphery and inwards if the notch is formed in the inner radial periphery. For example, the opening angle may be zero (i.e., equal to 0°), so that the opposite walls of the notch in the circumferential direction are parallel in the radial direction.

[0037] Such a configuration can ensure that the pad is locked in place and that the forces are distributed favorably within the disc. This can help to preserve the disc and improve its reliability.

[0038] In some embodiments, the brake disc, for example the brake rotor disc, may include as many riders as there are reinforcement pads, each reinforcement pad being locked in position in the radial direction and in the axial direction within the notch in which said reinforcement pad is housed by a single rider.

[0039] The rider may also be known by a person in the trade by the English term "clip".

[0040] The rider can be engaged around a circumferential edge of the web, on the radial periphery of the web having the notches, overlapping in the circumferential direction of a portion of the web and a portion of the pad. The pad can have a stop portion configured to cooperate with the rider and ensure the pad is locked within the notch.

[0041] The bracket ensures that the pad is held in position within the notch, for example, within the "V"-shaped portion. For example, thanks to the bracket, it can be ensured that the forces exerted on the pad during braking via the torque-resistance element are adequately absorbed by the disc, the bracket only holding the pad in position without itself taking on any effort. This can help to preserve the disc, for example by avoiding significant force transmissions from the pad to the disc via the rider and a rider fixing to the disc, and to improve the reliability of the disc.

[0042] In some embodiments, each rider is fixed to the annular veil by a single rivet.

[0043] For example, the rivet can extend axially and pass completely through the web while being engaged with the rider. Such a single rivet can minimize the number of through holes required in the web, and thus reduce as much as possible the sources of web weakening. This can help preserve the web and improve the reliability of the disc.

[0044] In some embodiments, the brake disc, for example the brake stator disc, may include half as many riders as reinforcing pads, each reinforcing pad being locked in position in the radial direction and in the axial direction within the notch in which said reinforcing pad is housed by a single rider common with the adjacent reinforcing pad of the adjacent notch.

[0045] In other words, a single rider can lock the two adjacent pads in position by two adjacent notches. Such a rider can be fixed to the annular disc by exactly two rivets.

[0046] One embodiment relates to a method of manufacturing a carbon / carbon composite material reinforcement pad for a brake disc according to any one of the embodiments described in this exposition, wherein an annular web of carbon / carbon composite material from used or scrap brake disc is provided, and the reinforcement pad is machined within the annular web so that a compression modulus of the reinforcement pad is maximized in a direction perpendicular to a contact surface of the reinforcement pad configured to cooperate with a torque-recovery element.

[0047] Since carbon / carbon composite materials are very expensive and highly polluting, it is particularly advantageous from a financial and environmental standpoint to manufacture the brake pad from a used or scrap carbon / carbon composite part. Furthermore, by using used or scrap brake discs, the direction in which the compression modulus is maximum is known, generally the axial direction. Therefore, such a brake pad can easily be manufactured from such a disc at a lower financial and environmental cost.

[0048] In some embodiments, the reinforcing pad is machined so that the contact surface is derived from a braking friction surface (or braking track) of the annular disc.

[0049] The contact surface of the brake pad corresponds to a portion of the braking friction surface, or braking track, of the disc. Generally, within a carbon / carbon composite brake disc disc, the compression modulus is maximum along the axial direction, i.e., the direction perpendicular to the friction surface or braking track of the disc. It is therefore particularly easy and economical to machine such a brake pad from such a disc. Brief description of the drawings

[0050] The purpose of this presentation and its advantages will be better understood upon reading the detailed description below of various embodiments given by way of non-limiting examples. This description refers to the attached figure pages, on which:

[0051] [Fig. 1] Fig. 1 represents a partial view of an aircraft brake,

[0052] [Fig.2] Fig.2 represents a partial view of a brake disc of the brake of the [Fig. 1], one of the riders being mounted, the other of the riders being approaching,

[0053] [Fig.3] The [Fig.3] represents a partial view of the brake disc of the [Fig.2], without the riders, seen along the axial direction, along arrow III of the [Fig.2],

[0054] [Fig.4] Fig.4 represents the brake disc as seen in Fig.3, in exploded view and with the riders,

[0055] [Fig. 5] [Fig. 5] shows a partial view of the brake disc of [Fig. 2], viewed in the radial direction, along arrow V of [Fig. 2], and

[0056] [Fig.6] Fig.6 represents different stages of a manufacturing process for a skate. Description of the implementation methods

[0057] Fig. 1 partially represents an example of an aircraft brake 100. For clarity of the figure, only the brake discs and torque-retaining elements are shown, the brake shoes and pistons, which are otherwise well known to those skilled in the art, are not shown.

[0058] In this example, the brake 100 comprises a plurality of rotor brake discs 10, in this example four rotor brake discs 10, and a plurality of stator brake discs 40, in this example five stator brake discs 40 (only one stator disc 40 being visible in [Fig. 1]), the rotor discs 10 alternating with the stator discs 40 in the axial direction X. According to an alternative not shown, there may be more or fewer rotor discs 10 and stator discs 40, the principle being an alternation of rotor discs 10 and stator discs 40 in the axial direction X and the presence of N+1 stator discs 40 for N rotor discs 10, N being an integer greater than or equal to 1. According to another alternative, one of the stator discs arranged at an axial end of the stack of discs may be different from the other stator discs.

[0059] In this example, the rotor discs 10 are rotationally coupled to a wheel 400 of an aircraft landing gear via a plurality of torque-retaining elements 50, also known as "torque-retaining bars" by those skilled in the art, which are fixed to the wheel 400. In [Fig. 1], for clarity, only a portion of the rim of the wheel 400 is symbolically represented by dashed lines, and only one torque-retaining element 50 is shown, such a wheel 400 and such a plurality of torque-retaining elements 50 being otherwise well known to those skilled in the art. The stator discs 40 are rotationally coupled (i.e.in a static manner) via a plurality of torque-retaining elements 52 with a fixed part 402 rotating from the brake 100, in this example a torque-retaining tube 402, the torque-retaining elements 52, also known as the "rail" by those skilled in the art, being fixed to the part 402. In [Fig. 1] for clarity of the figure, only a portion of the part 402 is symbolically represented by dashed lines and only one torque-retaining element 52 is shown, such a part 402 and such a plurality of torque-retaining elements 52 being otherwise well known to those skilled in the art.

[0060] When the brake 100 is activated to brake the wheel 400, the pistons not shown axially press the rotor 10 and stator 40 discs against each other so as to create friction between the different adjacent discs to generate a braking torque, and this in a manner known to a person skilled in the art.

[0061] In this example, each brake disc 10, 40 comprises an annular web 12 made of carbon / carbon composite material extending along a radial direction R, an axial direction X, and a circumferential direction C. The annular web 12 has a radially external periphery 12A and a radially internal periphery 12B. A plurality of notches 14 (see [Fig. 4] – only one notch being shown in the figures) are provided on the radially external periphery 12A or on the radially internal periphery 12B of the annular web 12, each notch 14 being through-hole along the axial direction X. In this example, the notches 14 of the rotor discs 10 are provided on the radially external periphery 12A and the radially internal periphery 12B is notched, while the notches 14 of the stator discs 40 are provided on the radially internal periphery. 12B and the radially external periphery 12A is notched.Each notch 14 is provided with a pair of reinforcing pads 16 made of carbon / carbon composite material arranged opposite each other along the circumferential direction C, an axial groove 18 being provided between each pair of pads, the axial groove 18 being configured to receive a torque-retaining element 50, 52, each reinforcing pad 16 having a flat contact surface 16A and configured to cooperate with the torque-retaining element 50, 52, the web. annular 12 having a compression modulus which is maximum along the axial direction X while each reinforcing pad 16 has a compression modulus which is maximum along a direction E perpendicular to the contact surface 16A (see [Fig.3]).

[0062] In this example, the rotor discs 10 and the stator discs 40 are all equipped with pads 16. According to an unrepresented variant, only the rotor discs 10 or only the stator discs 40 can be equipped with such pads 16.

[0063] Subsequently, with reference to Figures 2 to 5, only one rotor disk 10 is described in more detail, but this description is applicable to the stator disks 40. Similarly, a single notch 14 and the associated pair of pads 16 are described in more detail, but this description is applicable to all the notches 14 and the associated pairs of pads 16 of the plurality of notches 14 of each disk.

[0064] The notch 14 forms a groove that opens radially outwards EXT and extends parallel to the axial direction X. In this example, each pad 16 covers the entire lateral wall 14A, comprising in this example a radial wall 14A1 and a portion of the bottom wall 14A2, of the notch 14, over its entire radial and axial extent. The contact surface 16A of each pad 16 extends over the entire radial and axial extent of the notch 14.

[0065] The axial groove 18 can be delimited by the contact surfaces 16A of the two facing pads 16, and by a main bottom wall 14B of the notch 14. In other words, the contact surfaces 16A form the lateral walls 18A of the groove 18 and the main bottom wall 14B of the notch 14 forms the bottom wall 18B of the groove 18. In this example, the main bottom wall 14B extends substantially perpendicularly to the radial direction R.

[0066] In this example, each reinforcing pad 16, and in particular the contact surface 16A of each pad 16, extends radially beyond the periphery 12A where the notch 14 housing said reinforcing pad 16 is provided, opposite the bottom 18B of the axial groove 18. In this example, each reinforcing pad 16, and in particular each contact surface 16A, extends radially below the bottom 18B of the axial groove 18 within the annular web 12, opposite said periphery, in this example the radially external periphery 12A (see [Fig.3]).

[0067] In this example, each reinforcing pad 16 cooperates by complementarity of form with a radial wall 14A1 and a portion of bottom wall 14A2 of the notch 14 in which said reinforcing pad 16 is housed, so as to radially and circumferentially lock the reinforcing pad 16 within said notch 14 when reinforcing pad 16 is subjected to a circumferential force pushing the reinforcing pad 16 against said radial wall 14A1.

[0068] In this example, the notch 14 has, considered along the axial direction (see figures 3 and 4), two V-shaped portions 15, the opening of the V of each V-shaped portion 15 opening into the notch 14 by being arranged opposite each other, each V-shaped portion 15 receiving a reinforcing pad 16 and cooperating by complementarity of form with said reinforcing pad 16.

[0069] In this example, the two V-shaped portions 15 of the notch 14 are arranged on either side, along the circumferential direction C, of ​​the main bottom wall 14B. In this example, each V-shaped portion 15 is delimited by a radial wall 14A1 and by a bottom wall portion 14A2 of the notch 14, each of these walls forming a branch of the V shape. The two bottom wall portions 14A2 are distinct from the main bottom wall 14B and are arranged on either side of the main bottom wall 14B along the circumferential direction C. The point of the V of each V-shaped portion 15 is arranged opposite, along the circumferential direction C, the main bottom wall 14B, with respect to the bottom wall portion 14A2.Considered along the radial direction R, the main bottom wall 14B is disposed further out (or towards the periphery) than the distal end of the branch of the "V" formed by the portion of the bottom wall 14A2. In other words, a step 13 extending radially and axially is formed between the portions of the bottom wall 14A2 and the main bottom wall 14B, this step 13 forming a wedge receiving a portion of the skate 16 and allowing the contact surface 16A to extend radially in front of the main bottom wall 14B.

[0070] In this example, the two branches of the "V" of each "V" shaped portion 15 form an angle al between 70° and 100°, in this example 90°, one branch 14A1 of the "V" of each "V" shaped portion 15 forming an angle a2 between 10° and 30°, in this example 20°, with the radial direction R.

[0071] Since the V-shaped portions 15 are opposite each other, angle a2 of one V-shaped portion 15 is oriented opposite to angle a2 of the other V-shaped portion 15. In other words, the lateral walls 14A1 of the same notch 14 move circumferentially closer to each other when moving radially in the direction oriented from the inside INT to the outside EXT. In the case where the notch 14 is formed in an inner periphery, as for example for the stator brake disc 40, the lateral walls of the same notch move circumferentially closer to each other when moving radially in the direction oriented from the outside EXT to the inside INT.

[0072] In this example, the contact surfaces 16A of the two reinforcing pads 16 of each pair of reinforcing pads 16 together form, considered along the axial direction, a truncated "V" shape (see [Fig. 3]), the opening angle a3 of the truncated "V" being between 0° and 25°, in this example 10°. In this example, The opening of the truncated "V" is oriented outwards EXT. In the case where the notches are formed in a radially internal periphery, the opening of the truncated "V" is oriented inwards INT, and the contact surfaces 16A of the two pads 16 of each pair of pads can for example be parallel (a3 = 0).

[0073] The complementary shape of the V-shaped portion 15 with the pad 16, and the opening angle of the truncated V formed by the contact surfaces 16A of the pair of pads 16, allow the pads 16 to self-lock within the V-shaped portion 15 when the torque-absorbing element 50 presses against a pad 16 during torque absorption during braking. Arrows Fl and F2 in [Fig. 3] represent, respectively, the circumferential and radial components experienced by a pad 16 during such torque absorption, these components locking the pad 16 within the V-shaped portion 15.

[0074] In this example, the disc 10 comprises as many clips 20 as there are reinforcing pads 16, each reinforcing pad 16 being locked in position along the radial direction R and along the axial direction X within the notch 14 in which said reinforcing pad 16 is housed by a single clip 20. As can be seen in Figures 2 and 5, the clip 20 has a substantially U-shaped cross-section and is engaged around the circumferential edge of the web 12 forming the radial periphery 12A, overlapping along the circumferential direction with the pad 16. The clip 20 locks the pad 16 in the radial direction outward EXT (or inward INT if the notch is provided on the inner periphery) and axially clamps the pad 16 so as to lock it along the axial direction X. This makes it possible to lock the pad 16 within the V-shaped portion » 15.Since the V-shaped portion 15 absorbs the vast majority, if not all, of the braking forces, the bracket 20 may not absorb any of these forces and serve only to block or hold the pad 16 within the V-shaped portion 15. In this example, each bracket 20 is fixed to the disc by a single rivet 22. The rivet 22 extends axially and passes completely through the bracket 20 and the disc 12. The bracket 20 may be metallic and may be formed by folding. The rivet 22 may be metallic.

[0075] According to an unshown embodiment, a stator disc 40 comprises half as many riders as reinforcing pads, each reinforcing pad being locked in position in both the radial and axial directions within the notch in which said reinforcing pad is housed by a single rider common to the adjacent reinforcing pad of the adjacent notch. Each rider can be fixed to the annular disc by exactly two rivets.

[0076] In this example, the pad 16 has a stop portion 16B configured to cooperate with the rider 20 in the circumferential direction C. The contact surface 16A extends over the stop portion 16B. The stop portion 16B extends radially outwards EXT (or inwards INT if the notch is formed on the inner periphery). The jumper 20 is configured to prevent contact between sharp edges of the pad 16 and the bending radii 20A of the jumper 20. For example, the jumper 20 may have cutouts 20A opposite the edges of the pad 16. This can avoid complex machining of the pads 16, particularly chamfers that could be difficult to produce on a part of this size.

[0077] As shown in [Fig.5], the rider extends axially strictly between the braking tracks 11 of the web 12, i.e. does not extend axially beyond the braking tracks 11, when the disc 10 is new, these tracks being formed within the web 12 by a wear thickness EU (see [Fig.2]).

[0078] Figure 6 represents two steps of a PRO process for manufacturing a carbon / carbon composite material reinforcement pad 16 for a brake disc 10, 20 according to any one of the embodiments described in this exposition, in which, in a step E1, a carbon / carbon composite material web of used or scrap brake disc is provided, and then, in a step E2, the reinforcement pad 16 is machined within the web so that a compression modulus of the reinforcement pad 16 is maximum in a direction perpendicular to a contact surface 16A of the reinforcement pad 16 configured to cooperate with a torque-retaining element 50, 52.

[0079] In step E2, the reinforcing pad 16 can be machined so that the contact surface 16A is derived from a braking friction surface, or track, of the annular web.

[0080] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than a restrictive sense.

[0081] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

Demands

1. Brake disc (10, 40), for example for aircraft brakes (100), comprising an annular disc (12) of carbon / carbon composite material extending in a radial direction (R), an axial direction (X) and a circumferential direction (C), the annular disc (12) having a radially external periphery (12A) and a radially internal periphery (12B), a plurality of notches (14) being provided in the radially external periphery (12A) or in the radially internal periphery (12B) of the annular disc (12), each notch (14) being through-hole in the axial direction (X), each notch (14) being provided with a pair of reinforcing pads (16) of carbon / carbon composite material arranged opposite each other in the circumferential direction (C), an axial groove (18) being provided between each pair of pads (16), the axial groove (18) being configured to receive a torque take-up element (50, 52),each reinforcing pad (16) having a flat contact surface (16A) configured to cooperate with the torque-response element (50, 52), the annular web (12) having a compression modulus that is maximum along the axial direction (X) while each reinforcing pad (16) has a compression modulus that is maximum along a direction (E) perpendicular to the contact surface (16A).

2. Brake disc (10, 40) according to claim 1, wherein each reinforcing pad (16) extends radially beyond the periphery (12A, 12B) where the notch (14) housing said reinforcing pad (16) is provided, opposite the bottom (18B) of the axial groove (18), and / or extends radially below the bottom (18B) of the axial groove (18B) within the annular web (12), opposite said periphery (12A, 12B).

3. Brake disc (10, 40) according to claim 1 or 2, wherein each reinforcing pad (16) cooperates by complementarity of form with a radial wall (14A1) and a portion of bottom wall (14A2) of the notch (14) in which said reinforcing pad (16) is housed, so as to radially and circumferentially lock the reinforcing pad (16) within said notch (14) when reinforcing pad (16) is subjected to a circumferential force pushing the reinforcing pad (16) against said radial wall (14A1).

4. Brake disc (10, 40) according to any one of claims 1 to 3, wherein each notch (14) has, considered along the axial direction (X), two V-shaped portions (15), the opening of the V of each V-shaped portion (15) opening into the notch (14) being arranged opposite each other, each V-shaped portion (15) receiving a reinforcing pad (16) and cooperating by complementarity of form with said reinforcing pad (16).

5. Brake disc (10, 40) according to claim 4, wherein the two arms of the "V" of each "V"-shaped portion (15) form an angle (al) between 70° and 100°, one arm of the "V" of each "V"-shaped portion (15) forming an angle (a2) between 10° and 30° with the radial direction (R).

6. Brake disc (10, 40) according to any one of claims 1 to 5, wherein the contact surfaces (16A) of the two reinforcing pads (16) of each pair of reinforcing pads (16) together form, considered along the axial direction (X), a truncated "V" shape, the opening angle (a3) ​​of the truncated "V" being between 0° and 25°.

7. Brake disc (10, 40) according to any one of claims 1 to 6, comprising as many riders (20) as reinforcing pads (16), each reinforcing pad (16) being locked in position along the radial direction (R) and along the axial direction (X) within the notch (14) in which said reinforcing pad (16) is housed by a single rider (20).

8. Brake disc (10, 40) according to claim 7, wherein each rider (20) is fixed to the annular disc (12) by a single rivet (22).

9. Method (PRO) of manufacturing a reinforcement pad (16) of carbon / carbon composite material for a brake disc (10, 40) according to any one of claims 1 to 8, wherein an annular web of carbon / carbon composite material from used or scrap brake disc is provided (E1), and the reinforcement pad (16) is machined (E2) within the annular web (12) so that a compression modulus of the reinforcement pad (16) is maximum along a direction (E) perpendicular to a contact surface (16A) of the reinforcement pad (16) configured to cooperate with a torque-recovery element (50, 52). 17

10. Method (PRO) of manufacturing a reinforcing pad (16) according to claim 9, in which the reinforcing pad (16) is machined (E2) so that the contact surface (16A) is derived from a braking friction surface of the annular web.

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