BRAKE PAD AND ASSEMBLY METHOD

Abstract

Brake pad (18), the pad (18) comprising a lining (20) and a lining support (24), the lining (20) being made of friction material and provided with at least one particle collection groove, the lining support (24) being connected to a face (22B) of the lining (20), referred to as the mounting face, in which a space (29) is provided between the lining support (24) and the mounting face (22B) of the lining (20), a sealing housing (50) being arranged in said space (29), said sealing housing (50) comprising a suction channel (52) intended to be fluidly connected to a vacuum source, in which said at least one particle collection groove comprises a suction hole opening onto said sealing housing (50) and fluidly connected to said suction channel. Figure 4

Description

Title of the invention: BRAKE PAD AND ASSEMBLY METHOD Technical field

[0001] The present disclosure relates to the field of brake pads and methods of assembling these pads. Prior art

[0002] Conventionally, vehicle braking systems comprise a brake pad which, during braking phases, comes to bear against an element rotating around an axis of rotation, thus causing the vehicle to brake. In particular, in railway vehicles, such as trains, trams or metros, braking is carried out by means of a shoe brake, also called a tread brake or TBU (by its acronym in English "Tread Brake Unit"). In this type of brake, the brake pad, also called a shoe or tread, comes to bear, during braking phases, on a radially outer surface of a moving wheel of the railway vehicle.

[0003] The shoe of the brake shoe comprises a lining made of friction material. One face of this lining which comes into contact with the wheel during braking phases, called the friction face, as well as the wheel itself, gradually wears through abrasion, which generates particles. Since these particles are polluting, it is appropriate to limit their release into the environment. To this end, the lining is conventionally provided with a particle collection groove which is completely open on the friction face. This groove is fluidly connected to a vacuum source capable of sucking up the collected particles. For example, a pneumatic hose fluidly connects the groove to the vacuum source, as described in FR 3087238 A.

[0004] There is a need to develop pads that ensure that the connection between the pneumatic hose and the groove is reliable and tight, without increasing the size of the pad. Summary

[0005] The present disclosure improves the situation.

[0006] For this purpose, a brake pad is provided, the pad comprising a lining and a lining support, the lining being made of friction material and provided with at least one particle collection groove, the lining support being connected to a face of the lining, called the fixing face, in which a space is provided between the lining support and the fixing face of the lining, characterized in that a sealing housing is arranged in said space, said sealing housing comprising a suction duct intended to be fluidically connected to a source of depression, wherein said at least one particle collection groove comprises a suction hole opening onto said sealing housing and fluidly connected to said suction conduit.

[0007] Thus, thanks to the sealing housing, and in particular to the suction duct included in this housing, it is simpler to establish a reliable and sealed fluid connection between the collection groove and the vacuum source. Furthermore, since the sealing housing is arranged in the space between the lining support and the lining fixing face, already provided in the inserts of the prior art, the size of the insert is not increased by the presence of this sealing housing, and it is not necessary to modify its geometry compared to the inserts already known. The sealed and reliable fluid connection between the collection groove and the vacuum source can therefore be made without increasing the size and without modifying the geometry of the insert compared to the inserts already known.Furthermore, since the sealing housing is shaped to be installed in the space provided between the lining support and the lining mounting face, the maintenance operations of the pad are not modified. More precisely, the pad installed in a brake system can be replaced with a new pad in the same manner as in the prior art, as will be detailed.

[0008] The pad is for example a shoe (or block) of a shoe brake (or block brake, or TBU) of a railway vehicle. Alternatively, the pad may be a pad for a brake of a road vehicle or of a stationary rotor machine such as a wind turbine or an industrial machine.

[0009] The lining support may be shaped to be connected to a sole plate holder, for example via a pin configured to pass through at least one orifice provided in the lining support. The lining holder may comprise a sheet metal, made for example of a metallic material. In certain cases, the sheet metal comprises at least one folded region formed by two shoulders, which gives rise to the space provided between the lining support and the fixing face of the lining. Advantageously, said folded region may comprise an orifice arranged in each shoulder. Such orifices may allow the passage of the pin of the sole plate holder. Such a pin may be mounted movable in translation between a first position and a second position. In the first position the pin passes through the orifices of the lining support, so as to secure the plate and the sole plate holder.In the second position the pin is outside the holes in the pad holder, so as to separate the pad and the sole plate, which allows the pad to be replaced.

[0010] The particles collected in the at least one collection groove may be generated during the braking phases of the vehicle, during which the lining comes into contact with an element rotating about an axis of rotation. In particular, the lining may comprise a face, called a friction face, which is opposite the fixing face in a direction substantially perpendicular to the friction face. This friction face is intended to come into contact with said rotating element during the braking phases of the vehicle. The friction face and the rotating element thus wear during the braking phases, which generates the release of particles, generally pollutants, coming from the abrasion of the friction face and the rotating element. These particles can be collected in the at least one collection groove.

[0011] The at least one collection groove therefore makes it possible to limit the quantity of particles resulting from the abrasion of the lining and the rotating element which are released into the environment.

[0012] In some cases, the at least one collecting groove is completely open on the friction face of the lining. In other cases, said at least one collecting groove comprises a first part open on the friction face and a second part covered by friction material of the friction face. The second part of the at least one collecting groove being covered by friction material, this second part of the at least one collecting groove is open on the friction face only after the friction material covering it has been completely worn by the abrasion of the pad in contact with the rotating element during the braking phases. In particular, the second part of the at least one collecting groove is, initially, immersed in the lining.As the friction face of the pad wears through contact with the rotating element, the second portion of the collection groove emerges and opens onto the friction face. This prevents the second portion of the collection groove from being open onto the friction face before the wear level of the pad is sufficient for the rotating element to close the second portion of the at least one collection groove during braking phases. This limits the risk of particles resulting from wear of the pad or the rotating element, and collected in the at least one collection groove, escaping through the second portion of the collection groove before being sucked in by the vacuum source. The efficiency of the collection and suction of these particles is thus improved, since fewer particles are lost than if the collection groove were originally completely open on the friction face.

[0013] The trim further comprises a front edge and a rear edge, as well as an axially inner edge and an axially outer edge extending between said front and rear edges. In some cases, at least one of the axially inner or outer edges is a chamfered edge.

[0014] In the present text, "axial" means in a direction substantially parallel to the axis of rotation of the rotating element, while "radial" means any direction substantially perpendicular to the axis of rotation of the rotating element.

[0015] According to one example, the second portion of the at least one collection groove is disposed at least partially under the chamfered edge. According to one example, the entire second portion of the at least one collection groove is disposed under the chamfered edge.

[0016] The rotating element is for example a wheel of a railway vehicle. The rotating element may alternatively be a brake disc. A radially external surface of the rotating element may have a substantially frustoconical shape. In particular, a diameter of said rotating element may gradually increase between an axially internal face and an axially external face of the rotating element.

[0017] Said suction hole of the at least one groove may open, directly or indirectly, onto said suction duct. According to a non-limiting example, the suction hole is arranged at one end of the at least one collection groove. The suction of the particles is thus concentrated at this end of the at least one collection groove. In addition, from a single suction hole it is possible to suck up the particles collected in the at least one collection groove. The manufacture of the wafer is thus facilitated and its size reduced.

[0018] The source of depression is for example a particle vacuum cleaner. Communication means, such as a flexible hose, can connect the source of depression to the suction hole.

[0019] The sealing housing may comprise a sealing body and a suction duct. According to a non-limiting example, the sealing body is at least partly arranged in the space provided between the lining support and the lining attachment face, while the suction duct projects from this space.

[0020] The suction duct may be connected to the sealing body. Furthermore, the suction duct may be intended to be fluidically connected to the vacuum source. In particular, one end of the communication means may be connected to the suction duct, while another end of the communication means may be connected to the vacuum source. Advantageously, an external surface of the suction duct may comprise at least one annular protrusion. This makes it possible to secure the connection of the communication means to the suction duct.

[0021] Advantageously, when the sealing housing is installed in the space provided between the lining support and the fixing face of the lining, the at least one orifice provided in the lining support for the passage of the pin is not closed by the sealing housing. Thus, it is always possible to connect the plate to the sole plate holder by inserting the pin into said at least one orifice of the lining support. The presence of the sealing housing therefore does not modify the maintenance operations of the plate, which can be replaced when the pin is disengaged from the at least one orifice of the lining support and the communication means disconnected from the suction duct. In addition, as explained above, the housing can be installed in the plates of the prior art without modifying their geometry or their size.

[0022] The sealing housing may be a part added in the space provided between the lining support and the fastening face of the lining. This configuration has the advantage of not requiring modification of the method of assembling the lining to the lining support. Alternatively, the sealing housing may be integrated into the lining support and / or the lining. This avoids having to provide means for holding the sealing housing in position in the space provided between the lining support and the fastening face of the lining.

[0023] The sealing housing is advantageously connected in a sealed manner to the lining of the wafer, and therefore, to each collection groove of the wafer. The sealing between the housing and the lining (and between each collection groove) can be achieved for example from a rubber sheet or mastic, by molding the lining on the housing, or by a O-ring arranged between the suction hole and the housing.

[0024] According to one aspect, the sealing housing is welded to the gasket support and / or to the gasket.

[0025] This configuration allows the housing to be installed in the space provided between the lining support and said fixing face without modifying the structure of the lining support or the lining. Thus, the sealing housing can be installed on already existing plates which include a space between the lining support and the fixing face of the lining. Furthermore, there is no need to use additional parts to hold the sealing housing in position in the space provided between the lining support and the fixing face of the lining.

[0026] To carry out the welding, the sealing body may comprise a shell, for example a metal shell. The shell may delimit a housing of the sealing body. The shell may be welded to a face of the gasket support which is arranged opposite the fixing face of the gasket. Thus, a weld bead appears between the gasket support and the sealing housing.

[0027] If the sealing housing is welded onto the gasket, the gasket may advantageously comprise a metal zone for carrying out the welding.

[0028] According to one aspect, the plate may further comprise a connecting means connecting the sealing housing to the packing support and / or the packing. Thus, the sealing block is reliably connected to the packing support and / or the packing.

[0029] The connecting means may be a non-removable or removable means. The connecting means may be, for example, a screw. In order to connect the housing to the gasket support by the connecting means, the sealing body may comprise a cavity comprising a complementary thread of a thread of the connecting means. Furthermore, the packing support may comprise a bore aligned with the cavity of the sealing body and shaped to receive the connecting means. It is thus possible to connect the sealing housing to the packing support from the connecting means to hold it in position in the space provided between the packing support and the fixing face of the packing.

[0030] It is noted that the sealing housing shaped to be connected to the lining support by the connecting means may otherwise comprise the same elements as the sealing housing shaped to be welded to the lining support and / or to the lining. It is noted, however, that in order not to increase the dimensions of the sealing housing, the housing of the shell described above may be smaller than when the sealing housing is welded.

[0031] According to one aspect, the sealing housing is tightly mounted in said space provided between the lining support and the fastening face of the lining. This configuration also makes it possible to install the housing in the space provided between the lining support and said fastening face without modifying the structure of the lining support or the lining. Thus, the sealing housing can be installed on already existing pads which include a space between the lining support and the fastening face of the lining. Furthermore, there is no need to use additional parts to hold the sealing housing in position in the space provided between the lining support and the fastening face of the lining.

[0032] The sealing housing may in particular be mounted tightly in said space provided between the lining support and the fastening face of the lining by shrink fitting. For this purpose, initially the housing has dimensions which prevent its introduction into said space. The housing, or at least its sealing body, is then cooled. This cooling produces a contraction of the sealing housing which allows its introduction without effort into the space provided between the lining support and the fastening face of the lining. The temperature of the sealing housing then increases progressively until it reaches thermal equilibrium with its environment (in particular with the lining support and the fastening face). This increase in the temperature of the sealing housing causes the housing to gradually recover its original shape and dimensions.The sealing housing is then clamped between the gasket support and the gasket, in a watertight manner.

[0033] According to one aspect, the sealing housing may comprise a nut welded to the gasket support and / or the gasket, the nut comprising an internal annular face provided with a thread complementary to a thread provided on an external surface of said suction duct. Also, the suction duct may be connected to the nut by cooperation between the thread of the external surface of the suction duct and the thread of the nut.

[0034] To weld the nut to the lining support, a wall substantially perpendicular to the suction duct can be obtained by bending the sheet metal of the lining support or by welding such a wall to the lining support.

[0035] In some cases, to improve the seal between the sealing body and the suction duct, a seal, for example an O-ring, may be arranged at one end of the suction duct received in the sealing body.

[0036] According to one aspect, the sealing housing may comprise a filling block comprising a cavity fluidly connecting said suction hole of the at least one collection groove to said suction duct.

[0037] The filling block can be installed in the housing of the shell described above. The filling block can occupy the entire housing delimited by the shell. The cavity of the filling block extends for example between the suction hole and the suction duct, which makes it possible to fluidically connect the hole to the suction duct.

[0038] The filling block can also be obtained after overmolding the lining on the lining support.

[0039] According to one aspect, said filling block may be made of silicone and / or in the friction material of the lining.

[0040] When the filling block is made from the friction material of the lining, it is possible to obtain the filling block at the same time as the lining is overmolded onto the lining support.

[0041] In one aspect, the sealing housing may be made integral with the gasket support. In this manner, there is no need to provide additional parts or steps to connect the sealing housing to the gasket support when assembling the wafer.

[0042] According to one example, the sheet metal used to shape the gasket support may be designed to be bendable to form the sealing body of the sealing housing.

[0043] According to another example, at least one wall may be welded to the lining support, this wall extending substantially perpendicular to the suction duct. For example, two walls substantially perpendicular to the suction duct may be welded to the lining support to form a single piece. A housing formed between these walls and the lining support may be filled with friction material of the lining when the lining is overmolded on the lining support.

[0044] According to another aspect, there is provided a method of assembling a wafer as described above, the method comprising: - provide the gasket, gasket support and sealing housing; - connect the trim support to said trim fixing face; - arranging said sealing housing in said space provided between the lining support and the lining fixing face so that said suction hole of the at least one particle collection groove opens onto said sealing housing and is fluidically connected to said suction duct.

[0045] The method of assembling the pad is therefore simple. In particular, thanks to this method it is possible to install the sealing housing without the need to modify the shoe holder, which is very complex in the case of brake systems for railway vehicles. The seal between the suction hole, the suction duct and the vacuum source is therefore easily obtained.

[0046] According to one aspect, the sealing housing may be arranged in said space by at least one of the following techniques: - welding the sealing housing onto the gasket support and / or onto the gasket; and / or - fixing the sealing housing to the gasket support and / or to the gasket via a connecting means; and / or - shrink fitting of the sealing housing between the lining support and the lining; and / or - overmolding of the lining on an assembly comprising the lining support and said suction duct.

[0047] It is noted that it is possible to combine several of these techniques in the same plate to arrange the sealing housing in the space provided between the lining support and the fixing face of the lining. For example, the same housing can be both welded to the lining support and fixed by a connecting means to the lining support. This makes it possible to better guarantee that the sealing housing is held in position in the space provided between the lining support and the fixing face of the lining.

[0048] Advantageously, when the housing comprises a shell enclosing a housing occupied by the sealing block, and the housing is welded or fixed via a connecting means to the packing support and / or to the packing, the filling block is installed in the housing before connecting the sealing block to the packing and / or to the packing support. In the case of the exemplary embodiments in which the housing is welded or connected by a connecting means to the packing support and / or to the packing, it is possible to first connect the packing support to the fixing face of the packing, then install the sealing housing in the space provided between the packing support and said fixing face. In these examples, it is also possible to first connect the housing to the packing support and / or to the packing (by welding or by the connecting means), then connect the packing support to the fixing face of the packing.In this case, the step comprising connecting the trim support to the fixing face and the step comprising arranging the housing in the space provided between the support. of trim and said fixing face are produced concomitantly.

[0049] In the embodiments in which the lining is overmolded onto the assembly comprising the lining support and the suction duct, the step of arranging the housing in the space is also carried out concomitantly with the step comprising connecting the lining support and the lining. Brief description of the drawings

[0050] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: Fig.l

[0051] [Fig.l] shows a schematic perspective view of a braking system according to an exemplary embodiment. Fig. 2

[0052] [Fig.2] shows a schematic side view of a brake assembly of the braking system of [Fig.l]. Fig. 3

[0053] [Fig.3] shows a schematic perspective view of a brake pad of the braking system of [Fig.l] according to an exemplary embodiment. Fig. 4

[0054] [Fig.4] shows a schematic perspective view of the plate of [Fig.3] from a first angle, the plate being provided with a sealing housing. Fig. 5

[0055] [Fig.5] shows a schematic perspective view of the plate of [Fig.3] from a second angle, the plate being provided with the sealing housing. Fig. 6

[0056] [Fig.6] shows a schematic perspective view of an axial section of the plate of [Fig.3] and of a sealing housing according to a first embodiment. Fig. 7

[0057] [Fig.7] shows a schematic perspective view of an axial section of the plate of [Fig.3] and of a sealing housing according to a second embodiment. Fig. 8

[0058] [Fig.8] shows a schematic perspective view of an axial section of the plate of [Fig.3] and of a sealing housing according to a third embodiment. Fig. 9

[0059] [Fig.9] shows a schematic perspective view of an axial section of the plate of [Fig.3] and a sealing housing according to a fourth embodiment. Fig. 10

[0060] [Fig. 10] shows a schematic perspective view of an axial section of the plate of [Fig.3] and of a sealing housing according to a fifth embodiment. Fig. 11

[0061] [Fig. 11] shows a schematic perspective view of an axial section of the plate of [Fig.3] and of a sealing housing according to a sixth embodiment. Description of the embodiments

[0062] [Fig.l] shows an example of a braking system 10 for a vehicle, in particular a railway vehicle (train, tram, metro, etc.). The braking system 10 comprises a rotating element 12 and a brake assembly 14.

[0063] The rotating element 12 corresponds to a part of the vehicle causing translational movements of the vehicle thanks to a rotational movement of this element 12 around an axis of rotation. In this case, the rotating element 12 is a wheel of the vehicle configured to rotate around an axis of rotation A, without this being limiting.

[0064] Advantageously, a radially external surface 16 of the wheel 12 has a substantially frustoconical shape. In particular, a diameter of the wheel 12 increases progressively between an axially internal face 13A and an axially external face 13B of the wheel 12. In the present text, the axial direction corresponds to any direction substantially parallel to the axis of rotation A, and the radial direction corresponds to any direction substantially perpendicular to the axis of rotation A. Such a frustoconical shape of the radially external surface 16 makes it possible to guarantee the self-centering of the wheel 12 during the translation of the vehicle, and limits the risk of derailment of the latter in the curves present in its path.

[0065] As visible in [Fig.l], the wheel 12 may also comprise a flange 17 projecting radially from the axially internal face 13A of the wheel 12. Such a flange 17 also reduces the risk of derailment of the vehicle.

[0066] The brake assembly 14 comprises a brake pad 18, also called a sole or shoe. The pad 18 comprises a lining 20 made of friction material. The lining 20 comprises a first face, called the friction face 22A, arranged radially opposite the radially external surface 16 of the wheel. The friction face 22A is substantially curved.

[0067] As will be detailed, the friction face 22A is intended to come into contact with the radially external surface 16 of the wheel 12 during the braking phases of the vehicle.

[0068] The lining 20 comprises a second face 22B, called the fixing face, opposite the friction face 22A. In particular, the friction faces 22A and the fixing faces 22B are opposite in the axial direction.

[0069] The lining 20 further comprises an axially internal edge 22C, an axially external edge 22D, a front edge 22E, and a rear edge 22F. The edges 22C, 22D, 22E and 22F extend substantially radially between the friction 22A and fixing 22B faces.

[0070] The axially inner edge 22C and the axially outer edge are opposite in the axial direction. These axially inner and outer edges 22C, 22D connect the front edge 22E and the rear edge 22F to each other.

[0071] As can be seen from Figures 1 and 3, the axially inner edge 22C may be chamfered.

[0072] The front edge 22E and the rear edge 22F are defined with respect to a direction of rotation of the wheel 12. In the example of [Fig.l], it is assumed that the wheel 12 rotates in a direction R around the axis A. The front edge 22E corresponds to the edge of the lining 20 which is seen first by a specific point P imagined on the wheel 12 when it rotates around its axis of rotation A in the direction R, while the rear edge 22F corresponds to the edge of the lining 20 which is seen last by the specific point P when the wheel 12 rotates around its axis of rotation A in the direction R. Of course, the direction of rotation R could be opposite to that marked in [Fig.l], which would reverse the position of the front 22E and rear 22F edges.

[0073] As will be detailed later, the lining 20 comprises at least one particle collection groove.

[0074] The brake assembly 14 may further comprise a lining support 24, visible in particular in [Fig. 2]. The lining support 24 may comprise a sheet 25, for example made of metallic material. The lining support 24 is connected, directly or indirectly, to the fixing face 22B of the lining 20.

[0075] The sheet 25 may comprise at least one folded region 26, visible in FIGS. 3 and 4. In this case, the folded region 26 comprises a first shoulder 26A and a second shoulder 26B facing each other. The first shoulder 26A comprises an orifice 27A, and the second shoulder comprises an orifice 27B. Preferably, the orifices 27A and 27B are facing each other.

[0076] As can be seen from [Fig. 3], when the lining support 24 is connected to the fixing face 22B, the folded region 26 projects relative to the rest of the sheet 25 which is in contact with the fixing face 22B. Thus, a space 29 exists between the lining support 24 and the fixing face 22B of the lining 20. This space is delimited between the folded region 26 of the sheet 25 and the fixing face 22B of the lining 20.

[0077] The brake assembly 14 may also be provided with a shoe holder 28. The shoe holder 28 is connected to the lining support 24. In particular, as visible in [Fig. 2], the shoe holder 28 may comprise a pin 31. The pin 31 is shaped to pass through the orifices 27A, 27B provided in the lining support 24. The pin 31 may in particular be mounted movable in translation between a first position in which it passes through the orifices 27A, 27B of the lining support 24, and a second position in which the pin 31 is outside the orifices 27A, 27B. Thus, in the first position of the pin 31, the plate 18 is secured to the sole holder 28, while in the second position of the pin 31 the plate 18 can be detached from the sole holder 28, for example to be replaced by another plate 18.

[0078] The brake assembly 14 is configured to move the shoe holder 28, and therefore the pad 18. During the braking phases of the vehicle, the brake assembly 14 is configured to move the pad 18 in a direction bringing it closer to the wheel 12 until the friction face 22A and the radially external surface 16 of the wheel 12 come into contact, as visible in [Fig. 3]. Once the braking phase is complete, the brake assembly 14 is configured to move the pad 18 in a direction moving it away from the wheel 12, so that the contact between the friction face 22A and the radially external surface 16 of the wheel 12 ceases. Indeed, outside of the braking phases, the pad 18 and the wheel 12 are at a distance from each other, as illustrated in [Fig. 1].

[0079] When the friction face 22A of the pad 18 and the radially external surface 16 of the wheel 12 come into contact during the braking phases, the wheel 12 is moving in rotation about the axis A. A friction force is thus produced between the friction face 22A and the radially external surface 16, which causes wear of both the lining 20 of the pad 18 and the radially external surface 16 of the wheel 12. Particles, generally polluting, are thus formed by the abrasion of the friction material of the lining 20 and the wheel 12. During this wear, the friction face 22A of the lining 20 takes on the shape of the radially external surface 16 of the wheel 12.

[0080] As indicated previously, the lining 20 comprises at least one particle collection groove.

[0081] Each collection groove is open at least partially on the friction face 22A, as will be detailed later. Each collection groove extends in depth between the friction face 22A and the fixing face 22B. Each of the collection grooves is preferably a blind groove at an end opposite its opening on the friction face 22A. Also, each collection groove is shaped to recover the polluting particles resulting from the wear of the lining 20 and the wheel 12, and thus prevent these particles from being released into the environment.

[0082] [Fig. 5] shows a non-limiting example of the arrangement of the collection grooves in the lining 20. In particular, this lining 20 comprises a first main collection groove 30, a second main collection groove 32, a secondary collection groove 38, a first transverse collection groove 40 and a second collection groove 42. As will be detailed, all these grooves 30, 32, 38, 40, 42 are advantageously fluidically connected to each other, so that they form a single continuous collection groove.

[0083] The first main collection groove 30 is arranged near the front edge 22E. For example, the first main collection groove 30 is substantially parallel to the front edge 22E. The second main collection groove 32 is arranged near said rear edge 22F. For example, the second main collection groove 32 is substantially parallel to the rear edge 22F. By “near the front / rear edge” is meant here “at a distance from the front / rear edge less than or equal to 30% of the distance separating the front and rear edges, preferably less than or equal to 15% of the distance separating the front and rear edges”.

[0084] The presence of the main collection grooves 30, 32 near the front 22E and rear 22F edges makes it possible to guarantee the collection of polluting particles regardless of the direction of rotation of the wheel 12.

[0085] Advantageously, each main collection groove 30, 32 may comprise a first portion open on the friction face 22A and a second portion covered by friction material of the friction face 22A. The second portion of each groove 30, 32 is therefore immersed in the lining when the pad 18 is new or slightly worn. From a certain level of wear of the pad 18, the second portion of each groove 30, 32 emerges, that is to say, it also opens onto the friction face 22A. The second portion of each main collection groove 30, 32 may be arranged under the chamfered edge 22C, without this being limiting. Alternatively, a portion of the second portion could be immersed under the friction material of the friction face 22A, the remainder of the second portion being immersed under the chamfered edge 22C.

[0086] The secondary collection groove 38 is arranged between the first main collection groove 30 and the second main collection groove 32. According to a non-limiting example, the secondary collection groove 38 is located in a central position of the lining. By “central position” is meant here a position located substantially at the same distance from the front edge 22E as from the rear edge 22F of the lining 20. Of course, the secondary collection groove 38 could be closer to one of the front edges 22E or rear edges 22F, than to the other of these edges 22E, 22F.

[0087] The secondary collection groove 38 may extend substantially parallel to the primary collection grooves 30, 32, without this being limiting. For example, the secondary collection groove could be substantially parallel to only one of the two grooves 30, 32, or extend in a direction not parallel to the primary collection grooves 30, 32.

[0088] As can be seen from Figures 6 to 10, the secondary collection groove 38 may comprise a first portion 38-1 open on the friction face 22A, and a second portion 38-2 covered by friction material. The second portion 38-2 of the secondary collection groove 38 may be arranged entirely under the chamfered edge 22C. Alternatively, a portion of the second portion 38-2 of the secondary collection groove 38 may be immersed under the friction material of the friction face 22A, the remainder of the second portion 38-2 of the secondary collection groove 38 being immersed under the chamfered edge 22C. From a certain level of wear of the pad 18, the second portion 38-2 of the secondary collection groove 38 emerges, that is to say, it also opens onto the friction face 22A.

[0089] In some cases, the secondary collection groove 38 is fully open on the friction face 22A even when the pad 18 is new. In such cases, advantageously the secondary collection groove 38 is shorter, for example it has no portion extending into the chamfered edge 22C.

[0090] It is noted that even if in this [Fig.5] a single secondary collection groove 38 is provided, the lining 20 could comprise a plurality of secondary collection grooves 38 as described above.

[0091] The presence of the main collection grooves 30, 32 and the secondary collection groove 38 has the advantage of ensuring that, whatever the radius of curvature of the friction face 22A of the pad, the support of the friction face 22A on the wheel 12 during the braking phases is made opposite one of the grooves 30, 32, 38. It is thus possible to collect in the grooves 30, 32, 38 a greater quantity of polluting particles emitted by the abrasion of the pad 18 and the wheel 12. In addition, as indicated previously, the presence of the main collection grooves 30, 32 near the front 22E and rear 22F edges makes it possible to guarantee the collection of the polluting particles whatever the direction of rotation of the wheel 12.

[0092] The first transverse collection groove 40 fluidly connects the first main collection groove 30 and the secondary collection groove 38. In the non-limiting example of [Fig. 5], the first transverse collection groove 40 extends between one end of the first main collection groove 30 located opposite the axially external edge 22D of the lining 20, and one end of the secondary collection groove 38 located opposite the chamfered edge 22C. The first transverse collection groove 40 thus extends obliquely between the first main collection groove 30 and the secondary collection groove 38.

[0093] The second transverse collection groove 42 fluidly connects the second main collection groove 32 and the secondary collection groove 38. In the non-limiting example of [Fig. 7], the second transverse collection groove 42 extends between one end of the second main collection groove 32 located opposite the axially external edge 22D of the lining 20, and the end of the secondary collection groove 38 located opposite the chamfered edge 22C. The second transverse collection groove 42 thus extends obliquely between the second main collection groove 32 and the secondary collection groove 38.

[0094] In the present text, when it is indicated that the transverse collection grooves 40, 42 extend “at an angle” it is understood that they form a non-zero and non-right angle with each of the grooves that they connect. In this case, the first transverse collection groove forms a non-zero and non-right angle with the first main collection groove and the secondary collection groove, while the second transverse collection groove forms a non-zero and non-right angle with the second main collection groove and the secondary collection groove.

[0095] The first transverse collection groove 40 and the second transverse collection groove 42 are advantageously open on the friction face 22A. In the non-limiting example of [Fig. 7], the first and second transverse collection grooves 40, 42 are open over their entire extension on the friction face 22A. It is however possible to provide submerged parts on each of the first and second transverse collection grooves 40, 42.

[0096] Thanks to the presence of the transverse collection grooves 40, 42, the entire length of the lining 20 between the main collection grooves 30, 32 is crossed by at least one particle collection groove. This increases the surface area of ​​the lining opposite the collection grooves, which makes it possible to increase the quantity of polluting particles collected in the grooves and therefore, which are not released into the environment.

[0097] The fact that the first and second transverse collecting grooves 40, 42 extend at an angle is also advantageous. In particular, as indicated previously, during the braking phases, the radially external surface 16 of the wheel 12 wears concomitantly with the wear of the lining 20. The portion of the radially external surface 16 of the wheel 12 which is at each instant of the braking phase directly opposite one of the collecting grooves is not worn at this instant. Indeed, each collecting groove forms a recess in the friction face 22A. Each collecting groove therefore prevents friction forces from occurring between the friction face 22A and the radially outer surface 16 of the wheel 12. If the transverse collecting grooves 40, 42 connected the main collecting grooves 30, 32 and the secondary collecting groove 38 in a direction tangential to the portion of the radially external surface 16 which is in contact with the lining 20 during braking phases, an annular portion of the radially external surface 16 of the wheel 12 would never be in contact with the friction material of the friction face 22A. Ultimately, the radially external surface 16 of the wheel 12 would have an excess thickness on this annular portion compared to the rest of the radially external surface 16 of the wheel 12. Such an excess thickness can damage the rail on which the wheel 12 moves, and / or cause the vehicle to derail. In the present case, thanks to the transverse collection grooves 40, 42 at an angle, it is guaranteed that the contact time between any portion of the radially external surface 16 of the wheel 12 is negligible compared to the time that such a portion is in contact with the friction material of the lining 20. The wheel 12 is thus worn in a homogeneous manner, which avoids the appearance of excess thicknesses on its radially external surface 16.

[0098] Of course, the shape of the collection groove provided in the lining 20 of [Fig.5] is not limiting. Other shapes of collection groove can be envisaged.

[0099] As seen in Figures 6 to 10, the secondary collection groove 38 comprises a suction hole 44 which opens onto a sealing housing 50 which will be described in detail below. The collection groove formed by the main collection grooves 30, 32, the transverse collection grooves 40, 42, and the secondary collection groove 38 thus opens onto the sealing housing 50.

[0100] The suction hole 44 is intended to be connected to a vacuum source (not shown). The vacuum source is for example a particle vacuum cleaner. Communication means 45, visible in [Fig.l], can connect the vacuum source to the suction hole 44, in particular via the sealing housing. The particles collected in the collection grooves 30, 32, 38, 40, 42 can thus be sucked up. The communication means 45 comprise for example a flexible pneumatic pipe.

[0101] Preferably, the suction hole 44 is arranged at one end of the secondary collection groove 38. This concentrates the suction of the particles at this end.

[0102] The sealing housing 50 will now be described with reference to FIGS. 4 to 11.

[0103] The sealing housing 50 comprises a sealing body 51 and a suction duct 52.

[0104] The sealing housing 50 is arranged in the space 29 existing between the lining support 24 and the fixing face 22B of the lining 20. In particular, as is apparent from [Fig. 4], the sealing body 51 is at least partly arranged in the space 29.

[0105] As also visible in [Fig.4], the suction duct 52 projects from the sealing body 51 and the space 29. The suction duct 52 is connected to the body sealing 51.

[0106] The suction duct 52 is intended to be fluidically connected to the vacuum source. In particular, the communication means 45 may be connected to the suction duct 52, as illustrated in [Fig. 1]. More precisely, one end of the communication means 45 is connected to the suction duct 52, while another end of the means 45 is connected to the vacuum source. As visible in FIGS. 4 and 5, an external surface of the suction duct 52 may comprise at least one annular protrusion 54. In this case, three annular protrusions 54 are provided on the external surface of the suction duct, without this being limiting. Such annular protrusions make it possible to secure the connection of the communication means 45 to the suction duct 52.

[0107] Advantageously, when the sealing housing 50, in particular its body 51, is installed in the space 29, the orifices 27A and 27B are not closed by the sealing housing 50. Thus, it is always possible to connect the plate 18 to the sole plate holder 28 by inserting the pin 31 into the orifices 27A and 27B. The presence of the housing 50 therefore does not modify the maintenance operations of the plate 18, which can be replaced when the pin 31 is disengaged from the orifices 27A, 27B and the communication means 45 disconnected from the suction duct 52.

[0108] As visible in Figures 6 to 11, the sealing housing 50 can have different shapes. In Figures 6 to 8, the sealing housing 50 is a part added in the space 29, while in Figures 9 to 11, the sealing housing 50 is integrated into the gasket support 24 and / or the gasket 22, as will be detailed.

[0109] The examples of sealing housings of Figures 6 to 8 will now be described.

[0110] In the example of [Fig.6], the sealing body 51 comprises a shell 56. The shell 56 is advantageously made of metallic material. The shell 56 delimits a housing 58 inside which a filling block 60 is provided.

[0111] According to one example, the filling block 60 is made of silicone, but other materials are also conceivable. For example, the filling block 60 may be made of rubber that meets the fire-smoke requirements of railway applications. For example, the filling block 60 may be made of NBR rubber, which has improved thermal resistance. The filling block 60 preferably occupies the entire housing 58. As can be seen from [Fig. 6], the filling block 60 includes a cavity 62. The cavity 62 extends between the suction hole 44 and the suction duct 52, which allows the hole 44 to be fluidically connected to the suction duct 52.

[0112] To hold the sealing housing 50 in position in the space 29, in the example of [Fig.6] the sealing housing 50 is welded to the lining support 24. In particular, the shell 56 can be welded to a face of the lining support 24 which is arranged opposite the fixing face 22B of the trim 20. Thus, a weld bead 64 appears between the trim support 24 and the housing 50.

[0113] It is noted that advantageously, the filling block 60 is installed in the housing 58 of the shell 56 before the welding of the shell 56 onto the lining support 24. It is also noted that in certain cases, the housing 50 may be without a filling block 60, the seal between the suction hole 44 and the suction duct 52 being obtained thanks to the shell 56.

[0114] This configuration of [Fig.6] then makes it possible to install the sealing housing 50 in the space 29 without needing to modify the gasket support 24 or the gasket 20. The housing 56 welded according to the example of [Fig.6] therefore has the advantage of being able to be installed on already existing plates which include a space between the gasket support 24 and the fixing face 22B of the gasket 20.

[0115] The example of [Fig.7] differs from that of [Fig.6] in that the sealing housing 50 is connected to the packing support 25 via a connecting means 66, instead of via a welding bead 64. The connecting means 66 may be, for example, a screw, in particular a pressure screw screwed onto the packing support 24 (which may be threaded) and bearing on the outside of the housing 50. Alternatively, the connecting means 66 may be a shim bearing on the packing support 24 and screwed onto the housing 50 or a shim force-fitted between the packing support 24 and the housing 50.

[0116] In order to connect the housing 50 to the lining support 25 by the connecting means 66, the sealing body 51 may comprise a cavity 68 comprising a thread (not visible in [Fig.7]) complementary to a thread of the connecting means 66. Furthermore, the lining support 24 comprises a bore 70 aligned with the cavity 68 of the sealing body 51 and shaped to receive the connecting means 66. It is thus possible to connect the housing 50 to the lining support 24 from the connecting means 66 to hold it in position in the space 29.

[0117] The housing 50 according to [Fig.7] also comprises the same elements as the housing 50 according to [Fig.6]. These elements bear the same references in [Fig.7] as in [Fig.6] and, for the sake of brevity, are not re-described in the following. It should be noted, however, that in order not to increase the dimensions of the housing 50, the housing 58, and therefore the sealing block 60 (if provided), may be smaller than in the example of [Fig.6].

[0118] As in the case of [Fig.6], the filling block 60 is advantageously installed in the housing 58 of the shell 56 before connecting the shell 56 to the lining support 24 via the connecting means 66. As in the case of [Fig.6], the housing 58 can also be devoid of a sealing block 60.

[0119] In the example of [Fig.8], the housing 50 is mounted tightly in the space 29. In particular, the housing 50 can be mounted in the space 29 by shrinking. For this purpose, before to be introduced into the space 29, the housing 50, and in particular its body 51, has dimensions which prevent its introduction into the space 29. The housing 50, or at least its body 51, is then cooled. This cooling produces a contraction of the housing 50 which allows its effortless introduction into the space 29. The temperature of the housing 50 then increases progressively until it reaches thermal equilibrium with its environment (in particular with the lining support 24 and the fixing face 22B). This increase in the temperature of the housing 50 causes the housing to gradually return to its original shape and dimensions. The housing 50 is then clamped between the lining support 24 and the lining 20. In particular, the housing 50 is clamped in a sealed manner between the lining support 24 and the fixing face 22B of the lining 20.

[0120] This configuration of [Fig.8] then makes it possible to install the sealing housing 50 in the space 29 without needing to modify the gasket support 24 or the gasket 20.

[0121] For the sake of brevity, the elements that are identical or similar between the embodiment example of [Fig. 8] and those of Figures 6 and 7 have the same numbering in [Fig. 8] and are not described in detail in the following. It is noted only that in the example of [Fig. 8], the housing 58 of the shell 56 is devoid of a sealing block 60, but it could also include such a sealing block 60.

[0122] The examples of sealing housing 50 of FIGS. 9 to 11 will now be described.

[0123] In the example of [Fig. 9], the sealing housing 50 is made in one piece with the lining support 24. In particular, the sheet metal used to shape the lining support 24 is designed to be able to be folded so as to form the sealing body 51. The sealing body 51 comprises a first wall 51-1 and a second wall 51-2 substantially perpendicular to the suction duct 52 and placed between the first shoulder 26A and the second shoulder 26B. The suction duct 52 is for example carried by the second wall 51-2.

[0124] The sealing body 51 may also comprise in this example a third wall 51-3 connecting the first and second walls 51-1, 51-2 substantially parallel to the fixing face 22B. The third wall 51-3 may comprise a hole 72 arranged to be in fluid communication with the hole 44 of the gasket 20. The third wall 51-3 may also comprise at least one orifice 74 for retaining the gasket 20.

[0125] A housing 76, similar to the housing 58 described previously, is formed between the lining support 24, the first wall 51-1, the second wall 51-2 and the third wall 51-3. In the figures, this housing 76 is empty, but it could also include a filling block 60 like that of figures 6 and 7, or a filling block 60 made of friction material of the lining 20. The suction duct 52 and the suction hole 44 both open into the housing 58, so as to be fluidly connected to each other.

[0126] In this example, the lining 20 is overmolded onto the lining support 24 made in one piece with the housing 50. This overmolding causes the hole 72 and the at least one orifice 74 of the housing 50 to be filled, at least in part, with friction material of the lining 20. By introducing the friction material of the lining 20 into the hole 72 and into the at least one orifice 74, the adhesion of the lining 20 to the lining support 24 is improved.

[0127] It should be noted that to prevent the housing 76 from filling with friction material during the overmolding of the lining 20, the housing 76 is sealed during the overmolding of the lining 20. Thus, the housing 76 allows fluid communication between the suction hole 44 and the suction duct 52 without it being necessary to machine an additional cavity.

[0128] Similarly, it is noted that so that the part of the space 29 which is outside the housing 50 does not fill with friction material during the overmolding of the lining 20, this part of the space 29 is sealed during the overmolding of the lining 20. Thus, after overmolding of the lining 20, the orifices 27A, 27B of the lining support 24 are free to be able to receive the pin 31 of the sole holder 28.

[0129] Since in this configuration the housing 76 is not filled with friction material, the amount of material required to manufacture the pad 18 is reduced.

[0130] In the example of [Fig. 10], a first wall 78-1 and a second wall 78-2 are welded to the lining support 24. Also, the lining support 24, the first wall 78-1 and the second wall 78-2 form a single piece. In other words, they are made from a single piece.

[0131] The first and second walls 78-1, 78-2 extend substantially perpendicular to the suction duct 52. The suction duct 52 is carried by the second wall 78-2. A housing 80 is formed between the lining support 24 and the first and second walls 78-1, 78-2.

[0132] The lining 20 is overmolded onto the assembly comprising the lining support 24, the first and second walls 78-1, 78-2, and the suction duct 52. During overmolding, the housing 80 is filled with friction material of the lining 20, which makes it possible to seal this housing 80. The sealing body 51 therefore comprises in this case the walls 78-1, 78-2 and the friction material of the lining 20 filling the housing 80. In order to establish the fluid connection between the hole 44 and the suction duct 52, the cavity 62 described above with reference to [Fig. 6] is machined through the friction material filling the housing 80.

[0133] As for the example of [Fig.9], so that the part of the space 29 which is outside the housing 50 does not fill with friction material during the overmolding of the lining 20, this part of the space 29 is sealed during the overmolding of the lining 20. Thus, after overmolding of the gasket 20, the orifices 27A, 27B of the gasket support 24 are free to be able to receive the pin 31 of the sole plate holder 28.

[0134] [Fig. 11] shows another example of a sealing housing 50. In this case, the sheet metal of the gasket support 24 is folded so as to form a wall 82 substantially perpendicular to the suction duct 52. Alternatively, the wall 82 could be welded to the gasket support 24. The wall 82 is crossed by the suction duct 52. A nut 84 is welded to the gasket support 24. As visible in [Fig. 1 1], the nut 84 is for example welded to the wall 82.

[0135] The nut 84 comprises an internal annular face provided with a thread (not shown) which is complementary to a thread (not shown) provided on the external surface of the suction duct 52. Thus, the suction duct 52 is connected to the housing 50 by the cooperation between the thread of the suction duct 52 and the thread of the nut.

[0136] The sealing body 51 in this case therefore comprises the wall 82 and the nut 84. Furthermore, as visible in [Fig. 11], the sealing body 51 comprises a filling block 60 formed by friction material of the lining 24. This filling block 60 can be obtained after overmolding the lining 24 on the lining support 24 connected to the wall 82, the nut 84 and the conduit 52. To obtain this filling block 60, during the overmolding of the lining 20 a part of the space 29 is sealed during the overmolding of the lining 20, the other part remaining accessible to the friction material of the lining 20.

[0137] It is noted that as for the cases of [Fig.9] and 10, after overmolding of the lining 20 the orifices 27A, 27B of the lining support 24 are free to be able to receive the pin 31 of the sole plate holder 28.

[0138] As is apparent from [Fig.l 1], to improve the seal between the sealing body 51 and the suction duct 52, a seal 90 may be arranged at the end of the suction duct 52 received in the sealing body 51. The seal 90 is for example an O-ring.

[0139] The embodiments according to figures 9 to 11 have the advantage that the seal between the housing 50, the hole 44 and the suction duct 52 is obtained from the friction material of the overmolded lining 20. There is therefore no need for additional materials to ensure the seal.

[0140] Now a method of assembling the plate 18 according to one of the examples described previously will be described.

[0141] The method firstly comprises providing the packing 20, the packing support 24 and the sealing housing 50. Then, the method comprises connecting the packing support 24 to the fixing face 22B of the packing 20, and arranging the sealing housing 50 in the space 29 so that the suction hole 44 opens onto the sealing housing 50.

[0142] As explained previously, the sealing housing 50 can be arranged in the space 29 by: - welding the sealing housing 50 onto the gasket support 24, as in the example of [Fig.6]; - fixing the sealing housing 50 to the lining support 24 via the connecting means 66, as in the example of [Fig.7]; - shrinking of the sealing housing 50 between the gasket support 24 and the gasket 20, as in the example of [Fig.8]; - overmolding of the lining 20 on an assembly comprising the lining support 24 and the suction duct 52, as in the example of figures 9 to 11.

[0143] In the case of the embodiments of Figures 6 and 7, it is possible to first connect the packing support 24 to the fixing face 22B of the packing 20, then install the sealing housing 50 in the space 29. In these examples, it is also possible to first connect the housing 50 to the packing support 24 (by welding or by the connecting means 66), then connect the packing support 24 to the fixing face 22B of the packing 20. In this case, the step comprising connecting the packing support 24 to the fixing face 22B and the step comprising arranging the housing 50 in the space 29 are carried out concomitantly.

[0144] As indicated previously, in the examples of figures 6 and 7, the filling block 60 is installed in the housing 58 of the shell 56 before arranging the housing 50 in the space 29.

[0145] In the embodiments in which the lining 20 is overmolded onto the assembly comprising the lining support 24 and the suction duct 52, the step of arranging the housing 50 in the space is also carried out concomitantly with the step comprising connecting the lining support 24 and the lining 20. As explained previously, in the case of [Fig. 9], the housing 50 is carried entirely by the lining support 24. In the case of FIGS. 10 and 11, the housing 50 is formed in part by friction material of the lining 20 when the latter is overmolded onto the assembly comprising the lining support 24 and the suction duct 52. Also, in all the cases of FIGS. 9 to 11, the housing 50 is installed in its final position inside the space 29 when the overmolding of the lining 20 on the lining support 24 and the suction duct 52 is complete. trim 24 was made.

[0146] It is noted that it is possible to combine in the same plate 18 several of these techniques to arrange the sealing housing 50 in the space 29. For example, the same housing 50 can be both welded onto the lining support 24 and fixed by a connecting means 66 to the lining support 24. This makes it possible to better guarantee that the sealing housing 50 is held in position in the space 29.

[0147] The present disclosure is not limited to examples of brake pads and methods of assembling these plates described above, only by way of example, but it includes all the variants that a person skilled in the art may envisage within the framework of the protection sought.

Claims

Claims

1. Brake pad (18), the pad (18) comprising a lining (20) and a lining support (24), the lining (20) being made of friction material and provided with at least one particle collection groove (30, 32, 38, 40, 42), the lining support (24) being connected to a face (22B) of the lining (20), called the fixing face, in which a space (29) is provided between the lining support (24) and the fixing face (22B) of the lining (20), characterized in that a sealing housing (50) is arranged in said space (29), said sealing housing (50) comprising a suction duct (52) intended to be fluidically connected to a vacuum source, wherein said at least one particle collection groove (30, 32, 38, 40, 42) comprises a suction hole (44) opening onto said sealing housing (50) and fluidically connected to said suction conduit.

2. A plate (18) according to claim 1, wherein the sealing housing (50) is welded to the gasket support (24) and / or to the gasket (20).

3. Plate (18) according to one of the preceding claims, further comprising a connecting means (66) connecting the sealing housing (50) to the lining support (24) and / or to the lining (20).

4. Plate (18) according to one of the preceding claims, in which the sealing housing (50) is tightly mounted in said space (29) provided between the lining support (24) and the fixing face (22B) of the lining (24).

5. Plate (18) according to one of the preceding claims, in which the sealing housing comprises a nut (84) welded onto the lining support (24) and / or the lining (20), the nut comprising an internal annular face provided with a thread complementary to a thread provided on an external surface of said suction duct (52).

6. Plate (18) according to one of the preceding claims, in which the sealing housing (50) comprises a filling block (60) comprising a cavity (62) fluidically connecting said suction hole (44) of the at least one collection groove (30, 32, 38, 40, 42) to said suction conduit (52).

7. A pad (18) according to claim 6, wherein said filler block (60) is made of silicone and / or the friction material of the lining (20).

8. A plate (18) according to any preceding claim, wherein the sealing housing (50) is made integrally with the lining support (24).

9. A method of assembling a wafer (18) according to one of the preceding claims, the method comprising: - providing the lining (20), the lining support (24) and the sealing housing (50); - connecting the lining support (24) to said fixing face (22B) of the lining (20); - arranging said sealing housing (50) in said space (29) provided between the lining support (24) and the fixing face (22B) of the lining (20) so that said suction hole (44) of the at least one particle collection groove (30, 32, 38, 40, 42) opens onto said sealing housing (50) and is fluidically connected to said suction conduit (52).

10. An assembly method according to claim 9, wherein the sealing housing (50) is arranged in said space (29) by at least one of the following techniques: - welding the sealing housing (50) onto the packing support (24) and / or onto the packing (20); and / or - fixing the sealing housing (50) to the packing support (24) and / or to the packing (20) via a connecting means (66); and / or - shrink-fitting the sealing housing (50) between the packing support (24) and the packing (20); and / or - overmolding the packing (20) onto an assembly comprising the packing support (24) and said suction duct (52).

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