FR2698425A1 - Brake disc for rail traction unit - provided with vibration attenuator when brakes are applied. - Google Patents

Abstract

The brake disc consists of a hub (11), by which it is connected to the axle, and a flange (12) solidly fixed to the hub and to which the brake pads are applied during braking. On the outer surface of both the hub and the disc is machined a circumferential groove (18,19) into which is inserted a circular length of piano wire (16). The internal vibrations of the wire counteract those produced by the hub to reduce the noise generated during braking. USE/ADVANTAGE - As a vibration attenuator fitted to the disc of a brake unit on a rail traction unit. Simple to fit and effectively reduces the noise generated on braking.

Description

"Brake disc with vibration attenuator"
The present invention relates generally to brake discs, and it relates more particularly, but not necessarily exclusively, to those intended for equipping railway vehicles.

 As is known, a brake disc generally comprises, when it constitutes by itself a unitary assembly, a hub, by which it is adapted to be attached to the shaft to be braked, and a flange, which, arranged annularly around the hub, being duly secured thereto, possibly by elastic pins, is intended to be clamped between brake pads.

 The flange, which in a way forms the actual brake disc, is usually cast iron or forged steel.

 It can be in one piece, or, as is the case in particular for the brake discs commonly called "flanged", be split into two separate half-flanges, which, arranged back to back, each form respectively in directions opposite to each other, the two necessary friction surfaces.

 In all cases, such a flange is frequently the object of internal vibrations under the stress of the brake pads applied to it, in particular when it is made of steel and the friction lining of the brake pads is made of sintered metal.

 It is therefore inevitably a generator of unwanted noise.

 The present invention generally relates to a provision capable of minimizing, if not canceling, this noise.

 More specifically, it relates to a brake disc of the kind comprising a hub and a flange disposed annularly around this hub and duly secured thereto, this brake disc being generally characterized in that at at least any of the elements that constitute the flange and the hub is associated with at least one attenuating member, which, disposed in contact with this element, and, of course, suitably maintained with respect thereto, is capable of interfering with its possible internal vibrations.

 In short, the attenuating member used according to the invention constitutes a damping member which operates like a damper on a piano string or a finger on a bell to break any internal vibrations of the element in contact with which he is.

 Any generation of noise by it is therefore advantageously likely to be avoided.

 In addition, made of heat conducting material, this attenuating member is advantageously favorable to the cooling of the brake disc which it equips.

The characteristics and advantages of the invention will become more apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which
Figure 1 is a view partly in elevation and partly in axial section of a brake disc according to the invention
Figure 2 is a partial view in cross section along the line II-II of Figure 1
Figure 3 shows, on a larger scale, the detail of Figure 1 identified by an insert III in this Figure 1
Figures 4 and 5 are views which, similar to that of Figure 1, each relate respectively to two alternative embodiments
FIGS. 6, 7, 8, 9, 10, 11 are partial views in axial section which, also similar to that of FIG. 1, taking up, however, on a larger scale, only part of it, each also relates respectively to other alternative embodiments.

 As illustrated in these figures, and in a manner known per se, a brake disc 10 according to the invention comprises, on the whole, on the one hand, a hub 11, by which it is intended to be attached to a shaft to be braked , not shown, and, on the other hand, a flange 12, which, annularly arranged around the hub 11, while being duly secured thereto, is intended, for its part, to be clamped between brake pads, also not shown .

 Figures 1 to 3 illustrate more particularly by way of example the application of the invention in the case where, as shown, the flange 12 is solid and forms directly by itself, in one piece, on its two faces transverse 13 opposite, the friction surfaces specific to the intervention of the associated brake pads.

 The flange 12 thus formed is for example of steel.

 In the embodiment shown, it is attached to the hub 11 by elastic pins 15, and it extends in overhang at one of the ends of this hub 11.

 The corresponding provisions being well known in themselves, and not falling within the scope of the present invention, they will not be described in more detail here.

 According to the invention, it is associated, with at least any one of the elements that constitute the flange 12 and the hub 11, at least one attenuating member 16, which, disposed in contact with this element, and suitably maintained with respect to the latter is able to interfere with its possible internal vibrations.

 In the embodiment shown, such an attenuating member 16 is provided both for the flange 12 and for the hub 11.

 For the flange 12, it is, for example, and as shown, a cord which annularly surrounds this flange 12 on its peripheral edge, in the median zone thereof, and which, in the embodiment shown, is in round wire.

 However, as a variant, it may equally well be, for example, a ribbon.

 Anyway, the attenuating member 16 thus implemented is preferably under elastic stress, in the manner of a hoop.

 Preferably, also, it is made of a material which is not very elastic, and therefore absorbent with regard to sound.

 I1 can for example, and advantageously, be made of stainless steel, to be insensitive to atmospheric aggressions.

 But it may as well be for example copper or lead.

 Its section, here round, may in reality be arbitrary.

 In the embodiment shown, the attenuating member 16 is simply partly engaged radially in a groove 18 affecting in hollow the peripheral edge of the flange 12, which ensures its axial retention relative to the latter.

 More precisely, in this embodiment, this groove 18 has transversely a V section.

 For the hub 11, the attenuating member 16 is also, in the embodiment shown, a round wire bead which, partially engaged radially in a groove 19 of this hub 11, at a distance from the flange 12, annularly belts the hub 11 , being as before under elastic stress thereon.

 When it is made of a heat conductive material, and this is the case for example of copper, the attenuating member 16 according to the invention is favorable not only to minimization of the noise, but also to cooling, by forming a radiator .

 Figures 4 and 5 illustrate, by way of example, the application of the invention in the case where the flange 12, always in one piece, is ventilated.

 This flange 12 therefore comprises, internally, ventilation channels 20, which, generally radial, open on its peripheral edge, in the median zone thereof, thanks to a recess 21 of this peripheral edge.

 In FIG. 4, a single attenuating member 16 is provided, in the central region of the recess 21.

 I1 therefore interferes with the ventilation channels 20.

 As before, it is a round wire cord or the like which annularly surrounds the flange 12.

 As a variant, in FIG. 5, two attenuating members 16 are provided, which, each arranged respectively on either side of the recess 21, are without interference with the ventilation channels 20.

 Figures 6 to 8 illustrate by way of example the application of the invention to a "flanged" brake disc.

 The flange 12 of this brake disc comprises, in a manner known per se, two half-flanges 22, which, turned back to back, are each back-to-back with reprimand 23 of a wheel 24 coming in one piece from the hub 11 , on both sides of this soul 23.

 Each half-flange 22 is connected by a connecting web 25 to a support ring 26 by which it is abutted, and secured, for example by screws, not shown, to the corresponding end of the hub 11.

 The corresponding provisions being well known in themselves, and not falling within the scope of the present invention, they will not be described in more detail here.

 According to the invention, there is at least one attenuating member 16 which, according to provisions of the type of the preceding ones, annularly surrounds at least one of the half-plates 22 on the peripheral edge of the latter.

 In the embodiments shown, there is such an attenuating member 16 for each of the half-flanges 22.

 In these embodiments, there is in addition at least one other attenuating member 16 ′, 16 ″ inserted axially between at least one of the half-flanges 22, and in practice each of these, and the core 23 wheel 24.

 In practice, such an attenuating member 16 ′, 16 ″ extends annularly around the axis of the assembly.

 In FIG. 6, it is, as before, under the reference 16, a cord made of round wire, for example of steel, housed in a groove 28 annularly affecting the face of the half-flanges 22 by which those -these are attached to the core 23 of the wheel 24.

 In FIGS. 7 and 8, it is, under the reference 16 ", a simple washer, more or less thick, which is for example made of friction material.

 In FIG. 7, this washer is, as before, housed in an annular groove 29, duly enlarged, of the half-flanges 22.

 In FIG. 8, it is simply pinched between these and the core 23 of the wheel 24.

 Figures 9 to 11 illustrate, by way of example, the application of the invention in the case where the flange 12 is formed of two half-flanges 22 directly attached to each other.

 According to the invention, there is provided, in addition to an attenuating member 16 at the periphery of each of these two half-plates 22, an attenuating member 16 ', FIG. 9, or 16 ", FIGS. 7, 8, between them, according to arrangements of the type described above with reference to FIGS. 6 to 8.

 Furthermore, there is also provided, as shown, on the hub 11, at least one attenuating member 16.

 In the embodiments shown, this attenuating member 16 is disposed away from the central region of the hub 11.

 Of course, the present invention is not limited to the embodiments described and shown, but encompasses any variant and / or combination of their various elements.

Claims (10)

 1. Brake disc of the kind comprising a hub (11) and a flange (12) arranged annularly around the hub (11) and duly secured thereto, characterized in that to at least any one of the elements which constitute the flange (12) and the hub (11) is associated with at least one attenuating member (16, 16 ', 16 "), which, disposed in contact with this element, is capable of interfering with its possible internal vibrations.  2. Brake disc according to claim 1, characterized in that, the flange (12) being in one piece, there is at least one attenuating member (16) which annularly surrounds this flange (12) on the peripheral edge of it.  3. Brake disc according to claim 1, characterized in that, the flange (12) comprising two half-flanges (22) turned back to back, there is at least one attenuating member (16) which annularly belts one at least of said half-flanges (22) on the peripheral edge thereof.  4. Brake disc according to any one of claims 2, 3, characterized in that said attenuating member (16) is under elastic stress, in the manner of a hoop.  5. Brake disc according to claim 1, characterized in that, the flange (12) comprising two half-plates (22) each leaning against the core (23) of a wheel (24) on either side of there is at least one attenuating member (16, 16 ', 16 ") inserted axially between at least one of said half-flanges (22) and the core (23) of said wheel (24).  6. Brake disc according to claim 1, characterized in that, the flange (12) comprising two half-flanges (22) attached to one another, there is at least one attenuating member (16, 16 ' , 16 ") inserted axially between said half-flanges (22).  7. Brake disc according to any one of claims 5, 6, characterized in that said attenuating member (16, 16 ', 16 ") extends annularly around the axis of the assembly.  8. Brake disc according to any one of claims 1 to 7, characterized in that there is at least one attenuating member (16) which annularly encircles the hub (11).  9. Brake disc according to claim 8, characterized in that said attenuating member (16) is under elastic stress, in the manner of a hoop.  10. Brake disc according to any one of claims 1 to 9, characterized in that said attenuating member (16, 16 ', 16 ") is made of inelastic material, such as for example stainless steel, copper, lead, material friction.