FR2746472A1 - TORSION DAMPER WITH SPACER WASHER, ESPECIALLY FOR MOTOR VEHICLES - Google Patents

Abstract

The torsion damper comprises a web, a first guide washer, a hub (5), a spacer washer (6) and third elastic means (8). The spacer washer (6) internally comprises a first portion adjacent to the first guide washer and externally a second portion adjacent to the web and fixed in rotation with respect to said web. Said portions are offset axially and radially to form a cavity delimited by said portions, the web and the teeth of the hub (5). The third elastic means (8) are implanted in said cavity and overlap with circumferential clearance at least one tooth (73) of the teeth of the hub. Automotive vehicle application.

Description

The present invention relates to torsion dampers, particularly

  friction clutch for motor vehicles, comprising two coaxial parts mounted angularly movable relative to each other in a limited stroke, against first resilient means and first axially acting friction means, wherein one of the parts comprises two guide washers disposed on either side of a web belonging to the other coaxial part composed of the web and a coaxial hub angularly movable relative to each other, to the against second elastic means, in an angular deflection sector defined by complementary toothing, with circumferential clearance, of the web and the hub and wherein the first friction means comprise a spacer washer forming a spacer between the web and one of guide washers, said first guide washer, while third resilient means are provided and are interposed between the teeth of the web and the hub for r allow an engagement of said teeth with an effect

anti-noise braking.

  Such a damper is described in document FR-A-2 496 210.

  In it, the guide washers are integral with an input element capable of being rotatably connected to a driving shaft, while the hub forms

  an output element adapted to be secured in rotation to a driven shaft.

  In the case of a clutch friction, the input element consists of a friction lining support disk that can be clipped disengageably between the pressure and reaction plates which are integral with the rotation of the clutch. crankshaft of the engine constituting the driving shaft. The led tree is constituted by

  the input shaft of the gearbox.

  The third elastic means soften the circumferentially abutment positively abutting the teeth of the veil and the

hub, which prevents noise.

  In one embodiment, the third elastic means consist of at least one ring engaged around one of the teeth of said teeth in a groove of this tooth. The ring is adapted to be compressed by

  the teeth next to the other teeth.

  This provision gives satisfaction. Nevertheless to transmit more

  of torque it is desirable not to provide said tooth with a groove.

  The object of the present invention is to provide a simple and

3 5 economic to this wish.

  According to the invention a torsion damper of the type indicated above is characterized in that the spacer washer has internally a first portion adjacent to the first guide ring and externally a second portion adjacent to the web and through which the washer spacer is rotated relative to said web, in that said portions are axially and radially offset to form a cavity delimited by said portions, the web and the toothing of the hub extended for this purpose, and in that the third means elastics are implanted in said cavity and overlap at circumferential clearance at least one tooth of the teeth of the hub to cooperate with

  said tooth of the front hub engages the teeth of the web and the hub.

  Thanks to the invention the teeth of the hub and the sail are intact and the third elastic means are carried by the spacer washer obtained

  By molding, advantageously being made of moldable synthetic material.

  These third resilient means extend axially outside the web and parallel to the extended teeth of the hub. They extend only on one side of the veil and are not hindered by it. The spacer washer protects the third

  elastic means constituting a mask for them.

  Thus it is possible to easily implant the third resilient means to the outer periphery of the hub toothing since the spacer washer is distinct from the web and the hub. This is easy when the spacer washer has a bearing centering the guide washers relative to the hub. It is possible to form in advance a subset washer spacer - third elastic means and then mount said subassembly by threading on the web easily because the second elastic means center the web relative to the hub. In addition, the space available between

the teeth of the hub.

  Advantageously form-connecting means are provided between the web and the spacer washer to wedge said washer against the web. For example the second portion carries pawns

  cylindrical engaged in complementary holes made in the veil.

The opposite is possible.

  Thus, the spacer washer is indexed angularly with respect to the web and the toothing thereof and the mounting of the spacer washer on the web.

is easy.

  To do this, the pins are preferably engaged by force in the holes. Thus no circumferential clearance then occurs between the web and the washer, the free end of the pins being advantageously chamfered for

  facilitate mounting in the holes.

  In one embodiment the third elastic means consist of at least one block of elastomeric material hollowed out centrally to form a notch within which penetrates so

  complementary to circumferential clearance said tooth of the teeth of the hub.

  In one embodiment, at least one extra thickness is created in the spacer washer, said thickness being in the shape of a circular sector.

  with a central recess for mounting the block.

  Thus it is possible to force the block into the notch.

  Advantageously, at least two third elastic means are

  planned for a better distribution of efforts.

  The spacer washer may be shaped to carry part of the second elastic means so that the teeth of the web and the hub are

more robust and simplified.

  The third elastic means can be elastic by their shape. It may be for example curved metal blades carried by the edges or flanks of the central recess of the extra thickness to come into contact

  punctual with the concerned tooth of the hub and be compressed gradually.

  These blades can be connected together by a bottom and form a

  jumper mounted in said central recess.

  The following description illustrates the invention with reference to the drawings

  appended in which: - Figure 1 is an axial sectional view of the outer periphery of a clutch friction, its non-visible central portion being represented by an insert; - Figure 2 is a partial view in axial section to show one of the second elastic means that comprises the clutch friction; - Figure 3 shows on a larger scale the central portion of the clutch friction of Figure 1 identified by the insert 3 thereof; FIG. 4 is a view along the arrow 4 of FIG. 3 showing the bearing washer equipped with the third elastic means according to the invention, as well as the toothing of the hub, the second elastic means being removed for the sake of clarity; - Figure 5 is a view similar to Figure 3 for another embodiment;

  FIG. 6 is an axial sectional view along line 6-6 of FIG. 5.

  The damper shown in the figures is a clutch friction

for a motor vehicle.

  This friction includes torque transmission parts, here metallic, namely a support disc 1 implanted at the outer periphery of the friction and secured to two guide washers 2.3 disposed on either side of a web 4 surrounding, as well as guide washers 2,3, a central hub 5 generally of tubular shape and variable thickness. Friction thus presents a

axial axis X-X of symmetry.

  This friction also comprises friction parts, namely two annular friction pads 11, a first friction ring 31 surrounding a second friction ring 41 and a washer

  spacer 6. The washers 31, 41, 6 are here made of moldable synthetic material.

  The friction further comprises a first Belleville 32 axially acting washer surrounding a second Belleville washer 42 with axial action and lower stiffness than the first Belleville washer 32. In a variant, the washers 32, 32

  can be elastic washers having a wavy shape.

  This friction is provided with first coil springs 30, second coil springs 40 of lower stiffness than the first springs 30, support cups 43, here in synthetic material, dorsal face in the form of dihedron and front face carrying a centering stud. The second springs 40 are implanted radially below the first springs 30 and bear on each of their circumferential ends on the front face of a cup 43, whose centering pin penetrates inside said spring 40 for centering of

2 0 this one.

  The springs 30, 40 act in the circumferentially illustrated figures. The guide washers 2, 3 are connected to one another by spacers 12 in the form of columns which are also used for fixing the support disc 1

  attached to one of the guide washers 2,3, here to the guide ring 2.

  The spacers 12 each pass circumferentially a notch 22 formed at the outer periphery of the web 4 so that the relative angular movement between the web 4 and the guide washers 2,3 is limited by engagement of the spacers 12 with the edges circumferential

Notches 22.

  The support disc 1 door fastened at its outer periphery, radially beyond the guide washers 2,3, the friction linings 11

  disposed on either side of said disk 1.

  Said gaskets 11 are intended here to be clamped between the pressure and reaction plates of the clutch integral in rotation of the

crankshaft of the vehicle engine.

  They are secured here by riveting the disc 1. Alternatively they are glued to the disk 1. The hub 5 is grooved internally for its connection

  in rotation to the input shaft of the gearbox.

  The first Belleville washer 32 is supported on one of the guide washers 2,3, said second guide washer 3, and urges the first friction washer 31 in contact with the web 4 while tightening the spacer washer 6 between the other guide washer 2, said first guide washer, and the web 4. This first friction washer 31 carries at its outer periphery, from place to place, axially oriented pins centering the first Belleville washer and penetrating each into a complementary opening made in the second washer of

  guide 3 for connection in rotation therewith.

  The pins and the openings therefore form first rotational connection means 34. Second rotational connection means 44 intervene between the second friction washer 41 and the second guide washer 3 for rotating connection of the washers 3, 41. guide washer 3 has for this purpose notches at its inner periphery in which penetrate bosses from a tubular portion that has the second friction washer 41 at its inner periphery. The second Belleville washer 42 is centered at its inner periphery on said tubular portion and bears on its outer periphery on the second guide ring 3 to urge the second friction washer 41 in contact with the base of the end face. a flange 51 that has the hub 5 in extra thickness at its outer periphery. The flange 51 extends axially between the two guide washers 2,3 and passes through the web 4 extending on both sides thereof. The second Belleville washer 42, by action and reaction, clamps the spacer washer 6 between the first guide washer 2 and the hub 5. To do this, the washer 6 here comprises a tubular portion 61, forming a bearing, interposed radially between the internal periphery of the first guide ring 2 and the outer periphery of the hub 5. Here the hub 5 has at the base of its flange 51 a frustoconical portion 52 and the bearing 61 has at its front end a 3 o complementary frustoconical portion 62, coming into contact with each other under

  the action of the Belleville washer 42.

  The first guide ring 2 has at its inner periphery a transverse portion 24 connected to the main portion of the first guide ring 2 by an inclined portion 25. The washer 6, forming a bearing, matches the shape 35 of the first washer of guide 2 and has - in one piece - internally a first portion 64 of transverse orientation, in contact with its outer face with the portion 24, an intermediate portion 65 inclined, extending slightly clearance relative to the inclined portion 25, and externally a second portion 66

  of transverse orientation, the inner face of which is in contact with the veil 4.

  The first portion 64 is connected to the bearing 61.

  The inner faces, facing the web 4, of the first and second portions are thus offset radially and axially relative to one another and

  are connected to one another by here a cylindrical face of axial orientation 165.

  The intermediate portion 65 is thus of variable thickness with care for a space (volume) between the first 64 and second 66 portions and

  forming a clearance between the axial end of the flange 51 and the first portion 64.

  All this is obtained by shifting the portion 24 axially outwards (in

opposite direction to the veil 4).

  The inner periphery of the second guide ring 3 is also axially offset outwardly in the same way to accommodate the washers 41, 42. All this makes it possible to lengthen the flange 51, the guide washers

  2,3 being widened at their inner periphery.

  Furthermore, the second portion 66 carries axially projecting pins 67, in this case cylindrical with a circular section, engaged in complementary manner in circular holes 47 of the web 4, thus centered on the washer 6 forming an axial spacer between the first guide ring 2. and the veil 4, as well as between

  2 o the first guide washer 2 and the hub 5.

  This washer 6 centers the guide washers 2,3 and the sail 4 by

  relative to the hub 5 passing through the guide washers 2,3.

  As can be seen in FIG. 4, the washer 6 has a square shape with rounded edges (corners) for carrying the chamfered free end pins 67 for

  better penetrate the holes 47 without exceeding them.

  The first Belleville washer 32 thus urges the first guide ring 2 in contact with the outer face of the inner portion 64 of the washer 6 obtained easily by molding. This washer 6, like the friction washers 31, 44 also obtained by molding, is loaded to give it the

  3 o resistance and the desired coefficient of friction.

  Furthermore, the web 4 meshes circumferentially with the hub 5, so that the relative angular displacement between the web 4 is limited by the

  circumferentially engaging the teeth of the web 4 with teeth of the hub 5.

  More specifically, meshing means with circumferential clearance 7 3 5 intervene between the internal periphery of the web 4 and the outer periphery of the hub 5. The sail 4 has at its inner periphery a toothing 70 with teeth 72 of trapezoidal shape alternating with indentations , while the flange 51 has at its outer periphery a toothing 71 with teeth 73 also. of trapezoidal shape and of profile identical to those of the teeth 72, said alternating teeth

  circumferentially with indentations.

  The teeth 73 of the hub 5 are elongated axially and form

  splines. The web 4 is axially smaller than the fluted flange 51.

  The guide washers 2,3 are more spaced apart at their inner periphery than at their spacers 12. This is not a problem since here the springs 30 are housed in windows 15 of the washers 2,3, whose upper edges are provided with protruding lips to retain the springs 30. The axial spacing between said lips is generally equal to the axial spacing between the inner peripheries of the guide washers 2,3, whose conformation allows to shift

  axially outwards the washers 41,42 with respect to the washers 31,32.

  The axial size is thus not increased.

  The springs 30 are mounted in windows 45, 15 made in

  in the web 4 and the guide washers 2,3.

  The springs 40 are mounted in notches 48, 58 formed facing each other at the inner periphery of the web 4 and at the outer periphery.

of the flange 51.

  The indentations 48 are open towards the X-X axis, inward, while the indentations 58 are open in the opposite direction to the X-X axis, outwardly. The circumferential or lateral edges of the indentations 48, 58 are inclined so that a tip is formed when the clutch friction is at rest. The cups 43 have a shape complementary to that of said circumferential edges. Here two diametrically opposed crews of springs 40 with cups 43 are provided for resiliently coupling the web 4 to the hub 5. The springs 30 resiliently couple the guide washers 2.3 to the web 4 and are all mounted without play in the windows 15 guide washers. The number of springs 30 is a function of the applications. Here four pairs of coaxial springs are provided. These pairs of springs are regularly distributed at 90, two pairs of springs 30 are mounted without play in the windows 45 of the veil and the

  Two others with play for, in known manner, stepped intervention springs 30.

  Alternatively all the springs 30 can be mounted without play in the

windows 45 of the veil 4.

  Thus the guide washers 2,3 belong to a first coaxial portion and the web 4 has a second coaxial portion, itself composed of the web 4 and a hub 5 coaxial angularly movable relative to each other to against second elastic means (the cups 43 - springs) in an angular deflection sector, defined by complementary teeth 70,71 with circumferential clearance (meshing means a play

  circumferential 7) of the web 4 and the hub 5.

  The two coaxial parts 1,11,2,3-4,5 are angularly movable relative to each other in a limited stroke against first resilient means (the springs 30). The stroke is limited by engagement of the spacers 12 with the edges of the notches 22, alternatively this is achieved by coming with contiguous turns

  springs 30; the spacers 12 may in this case extend radially beyond

beyond the veil 4.

  Of course some of the springs 30,40 may be replaced by blocks of elastic material such as elastomer. The washers 31, 32.6 (the portion 64) belong to first friction means with axial action. The washers 41, 42, 61 (the bearing 61) belong to second friction means with axial action and with less friction than the first means of friction.

  friction so as not to obliterate the action of the springs 40 of low stiffness.

  The torsion damper thus comprises a main damper (disc 1 seals 11 - guide washers 2.3 - sail 4 - first elastic means 30 - first friction means 31, 32, 64) for filtering the vibrations in the

  driving range (or rolling) of the vehicle and a pre-damper (sail 4 -

  hub 5 - second elastic means 40,43 - second friction means

  41,42,61) for filtering vibrations in the engine idling speed range.

  During the relative angular displacement between the input element (the disc 1 and the liners 11), and the output element (the hub 5) of the torsion damper, a permanent friction occurs between the web 4 and the second washer of

Friction 5.

  In a first phase of travel, the washers 2, 3 form a block with the web 4 because the springs 30 are stiffer than the springs 40, which are then compressed until the clearance of the game meshing means 7 is canceled. A

  friction occurs between spans 52,62.

  After this phase the teeth 72 of the web 4 are circumferentially engaged with the grooves 73 of the flange 51, the web 4 is integral in rotation with the

  hub 5 and the springs 40 remain in their blind state.

  The springs 30 are thus compressed in a second phase and the first friction means come into action, thus in a delayed manner. A friction then occurs between, on the one hand, the first friction washer 31 and the web 4, and, on the other hand, between the first guide washer 2 and the bearing washer 6, in particular between the portions 64, 24. The engagement of teeth 72,73

created shocks and noises.

  For this reason there is provided third resilient means 8 interposed between the teeth 72,73 and adapted to allow a positive circumferential abutment of the teeth 70,71 of the web 4 and the hub 5 with a noise canceling effect. These third elastic means 8 soften the circumferential abutment of the teeth 70,71. More precisely, according to the invention, advantage is taken of the bearing washer 6 and in particular of its portions 64, 64 offset axially and radially with respect to each other. It is thus created a cavity 10 delimited by the portions 64,66, the

  sail 4 and the flange 51, specifically the toothing 71 extended for this purpose.

  According to the invention the third elastic means 8 overlap at circumferential clearance at least one groove 73 of the flange 51. The elastic means 8 extend axially parallel to the toothing 71 of the hub 5. They are recessed aixalement relative to the web. These third elastic means 8 consist in Figures 3 and 4 in at least one block of elastomeric material 8 hollowed out centrally to form a notch 81 of trapezoidal shape being narrower than the notch associated with the web 4. The notch 81 is

  implanted vis-à-vis a notch of the veil 4. Here several blocks 8 are provided.

  Thus the grooves 73 of the hub 5 penetrate radial clearance and circumferential clearance into the notches 81 and first engage the relevant edge of the notch 81 before engaging the teeth 72. The flange 51 here has six grooves 73 and the veil six notches. Blocks 8 extend to the periphery

  outer grooves 73, the bottom of the notches 81 extending radially to-

above grooves 73.

  It will be appreciated, thanks to the rotational connection of the washer 6 with the web 4 (pins 67 - holes 47), that it is possible to position the blocks 8 relative to the teeth 72 of the web 4, so that the grooves 73 come in contact with the blocks 8 before coming into contact with the teeth 72 (FIG. 4). The blocks 8 are compressed by the grooves 73 adjacent to the hub 5. Advantageously, the blocks 8 are steeper than the springs 30 for good vibration filtration. The

  30 springs 30 center the veil with respect to the hub 5.

  Here the teeth 70,71 are interrupted by the indentations 48,58

diametrically opposite.

  Here there are two blocks 8, which are diametrically opposed. These integral blocks of the bearing washer 6 may in one embodiment be adhered or glued to the inner face of the inner portion 64 and to the cylindrical face of axial orientation 165 interconnecting the inner faces of the portions 64, 66 Of course, it is possible to eliminate the notches 48, 58 and to replace them for example by two trapezoidal teeth of elastic material, such as elastomer, carried by the bearing washer 6, in the same way as the blocks 8, and penetrating without play in a notch complementary to the toothing 71 of the flange 51 of the hub 5 for forming the second elastic means 40. The additional teeth then have a lower stiffness than the blocks and can be hollowed out for this purpose . Alternatively the spacer washer may have two axial projections from its inner portion. The protrusions each enter a notch of the hub. On these projections is mounted an elastomeric ring cooperating with the

  two consecutive teeth 73 of the flange 51.

  In these figures, it will be noted that the wall 165 and the inner face of the wall 64 delimit here two thickenings 90, diametrically opposite, in the shape of a circular sector with a central recess 91 of axial orientation for mounting the block 8. The recesses 91 are open radially inwards

as the notches 48.

  These extra thicknesses are delimited circumferentially by two inclined edges parallel to the concemed edges of the teeth 72 adjacent to the web 4 while being in

withdrawal from them.

  The recess edges 81 of the block 8 protrude circumferentially against the circumferential edges of the neighboring teeth 72. As will have been understood, it is possible to axially mount the block in a recess

  91 easily achievable by molding.

  Of course, as a variant, the spacer washer 6 can present

  also notches 48 (Figures 5 and 6).

  In these figures the washer 6 has blocks 8 as in the

Figures 3 and 4.

  The blocks 8 are each located between two indentations 48

consecutive puck 6.

  As a result, the web 4 has no housing notch of the springs 40 so that it is stiffened, simplified and resiliently coupled to the web 4

3 0 via the washer 6.

  It is not possible to modify the hub 5 which, in FIGS. 3 and 4, has notches 58 and a toothing 71 extending over the entire length

axial flange 51.

  Here the notches 58 extend axially only opposite the notches 48, while the toothing 71 extends over the entire axial length of the flange. To do this the hub 5 is made for example by sintering. The hub 5 is also stiffened because it lacks notch 48 housing springs

  facing the teeth 70 of the veil 4.

  In these FIGS. 5 and 6, the washer 6 does not have an inclined intermediate portion transversely, as in FIGS. 3 and 4. This results from the fact that the portion 25 of the guide washer is more inclined and that the springs are implanted radially closer to the XX axis. The portions 65 and 66 of FIGS. 3 and 4 merge to form here the outer portion 166 offset axially and radially with respect to the inner portion 64 to which it is connected. The inner faces of the portions 64, 166 are of transverse orientation and

  offset radially and axially relative to each other.

  The pins 67 are associated with stiffening ribs 167

  extending parallel to the portion 25 at a distance therefrom.

  Alternatively it is possible to increase the number of teeth 72,73 by removing the notches 48,58, which allows the transmission of a higher torque.

  Indeed it is possible to provide other blocks similar to blocks 8.

  These blocks then overlap without play teeth 73. The additional elastomer blocks are of lower stiffness and constitute the second elastic means. For example, these blocks can be hollowed out internally and have cavities. These blocks then serve as elastic centering means between the web and the hub 5 while being for the rest position of the friction each in

  Contact with a groove 73 of the hub 5.

  We can multiply the number of blocks to increase the number of second elastic means. The second elastic means are then carried in part by the bearing washer 6 and intervene staggered manner, some additional blocks intervening after catching a game. The teeth of the veil 4 and

  hub 5 then have a simple shape being devoid of indentations.

  We can thus increase the number of teeth and transmit a couple

most important.

  In all cases the third elastic means 8 are resistant to centrifugal force and are allowed to be compressed by the adjacent tooth 73 of the hub 5

  and therefore to flute before canceling the game of meshing means to play 7.

  Of course, the present invention is not limited to the described embodiments. It is generally applicable to torsion dampers whose input portion is for example constituted by the support disk 1 or an extension of the first guide ring fixed on a flywheel integral with the crankshaft of the engine of the vehicle or more generally a driving tree. The hub 2, forming output element, integral in rotation with a driven shaft, can be rotated by means of tongues on the housing of a hydrokinetic coupling device. The springs 30, 40 may act radially. For example the springs 30 can be mounted using each of a hinge loop on the columns 12 and hinged on the web 4 then hollowed out using another loop mounted on an axis carried by the veil 4 The springs 40 can be mounted radially in the notches 48 and 58 of the web 4 and the hub 5

  as shown in EP-0 412 559.

  In this case we see that it is possible to make as in Figures 5 and 6 notches in the bearing washer 6 and in a portion of

  view of the flange 51 advantageously sintered material.

  The veil 4 is then devoid of indentation.

  The washer 6 can thus partly carry the second 40 and the third elastic means 8, the second elastic means may consist of

blocks of elastomeric material.

  Of course the washer 6 may be in two parts and include the bearing 61 rotatably connected to the first guide ring 2 in the same way as the second friction washer 41 that is to say using means of bond

  in rotation 44 of the type with bosses and notches.

  Portions 64,65,66 then belong to a spacer washer

  separate bearing the third elastic means 8.

  These third elastic means can be constituted by a

metal spring.

  For example, resilient blades can be mounted laterally in the recesses 91 and come into contact with the grooves 73 before

  these do not come into engagement with the teeth 72 and be compressed.

  Thus, according to the invention, the spacer washer 6 comprises an inner portion 64 and an outer portion 66, 166 offset axially and radially in

  so that the face 165 is not necessarily cylindrical axial orientation.

  The spacer washer 6 is thus recessed at its inner face facing the web 4, the portions 64,66,166 being adjacent respectively to the

  3 o guide washer 2 and to the sail 4.

  This allows the creation of a cavity 10 defined by said portions 64,66,166, the web 4 (the inner periphery thereof) and the hub 5 (the outer periphery thereof), more precisely by the toothing 71 of the hub 5 extended for this purpose. The third elastic means 8 are implanted in said cavity being carried by the spacer washer 6 and engaged between at least two consecutive teeth of the hub 5. These third elastic means are adapted to cooperate with the adjacent teeth of the hub 5 before coming into circumferential engagement

  70,71 teeth of the veil 4 and the hub 5.

  When the damper is in the rest position a circumferential clearance exists between the third elastic means 8 and the adjacent teeth 73 of the hub, so that the second elastic members 40 occur alone at the beginning of the relative angular displacement between the sail 4 and the hub 5. After (FIG. 4) the third elastic members 8 are compressed allowing a stop

circumferential teeth 72,73.

  Good vibration filtration and noise reduction are achieved. It will be appreciated in the embodiment of FIGS. 3 and 4 that

  Ring 8 is compressed gradually.

  Of course the pins 67 may be of rectangular section, for example square, and it is the same holes 47. It is possible to reverse the structures so that the web 4 can carry axially projecting pins engaged in

openings of the washer 6.

  The pawns may be ribbed and forcibly engaged by their

ribs in the holes of the veil.

  The spacers 12 may be from one of the washers of

  guidance, the first housing 45 of the web can be open to the outside.

  The first housings of the guide washers may consist of

2 0 embossed.

  The liners 11 may come into contact with a reaction plate mounted journalled on a first mass by means of a bearing means, such as a

ball bearing.

  The first mass is then intended to be fixed on the crankshaft of the internal combustion engine and elastic means with radial or circumferential action couple the first mass to the reaction plate. As can be seen in FIG. 5, the first guide ring 2 can be provided at the inner periphery with an annular flange of axial orientation coming into contact with the outer periphery of the bearing 61 and participating in the friction for contact with the

  Outer periphery of the bearing 61.

  The bearing surfaces 62, 52 are not necessarily tapered, the hub 5 being capable of being supported for axially locking the bearing 61 with a transverse front face and with an internal bore in contact with the outer periphery of the hub 5. This hub 5 may be less thick so that the second friction washer 41 can come into contact with the ends of the grooves 73. In this case it is necessary to insert a metal protection washer between the washer 41 and the end of the grooves 73. The portions 64, 66 and 166 are generally adjacent to the first guide ring and to the web 4. In effect an additional washer

  may be interposed between said portions and the guiding washer element - sail.

  As a variant, at least one of the guiding washer elements can be coated with a layer. All these provisions are intended in particular to obtain the desired coefficient of friction between the portion 64 and the first guide ring 2. There may therefore be a direct or indirect contact between the portions 64,66 and respectively the

  first guide washer and the sail 4.

  Of course the number of teeth of the teeth 70,71 depends on the

  applications. It is the same with the number of third elastic means.

Claims (11)

  A torsion damper, in particular clutch friction for a motor vehicle, comprising two coaxial parts (1, 2, 3, 4) mounted to move angularly with respect to each other in a limited stroke, against first resilient means (30) and first axially acting friction means (6,41,42), wherein one of said parts has two guide rings (2,3) arranged on either side of a web (4) belonging to the other 1 0 of said parts composed of the web (4) and a hub (5) coaxial movable angularly with respect to each other, against second elastic means (40 ), in an angular deflection sector defined by complementary toothing (70,71) with circumferential clearance of the web (4) and the hub (5), and wherein said first friction means comprise a spacer washer (6) forming spacer between the web (4) and one of the guide washers (2,3), said first guide washer ge (2), while third elastic means (8) are provided and are interposed between the teeth (70,71) of the web (4) and the hub (5) to allow engagement of said toothing with an effect of noise-reducing braking system, characterized in that the spacer washer (6) internally comprises a first portion (64) adjacent to the first guide ring (2) and externally a second portion (66, 166) adjacent to the web (4) via the intermediary of wherein the spacer washer (6) is wedged in rotation relative to said web (4), in that said portions are axially and radially offset for forming a cavity (10) delimited by said portions, the web (4) and the toothing (71) of the hub (5), and in that the third elastic means (8) are implanted in said cavity (10) and overlap at circumferential clearance at least one tooth (73) of the toothing (71) of the hub ( 5) to cooperate with said tooth   (5) before engaging the teeth (70,71) of the web (4) and the hub (5).   Shock absorber according to Claim 1, characterized in that the   Third resilient means (8) are recessed axially with respect to the web (4).   3. Shock absorber according to claim 1 or 2, characterized in that the third elastic means (8) consist of at least one elastomer block (8) hollowed out centrally to form a notch (81) inside which penetrates in a complementary manner circumferential clearance said tooth of the toothing (71) of the hub (5).   4. Shock absorber according to claim 3, characterized in that it is created   an extra thickness (90) in the spacer washer (6) for mounting said block (8).   5. Shock absorber according to claim 4, characterized in that said thickening (90) is in the form of a circular sector with a central recess (91)   axial orientation for mounting the block (8).   6. Damper according to claim 5, characterized in that the extra thickness (90) is delimited circumferentially by two inclined edges parallel to the relevant edges of teeth (72) adjacent to the toothing (70) of the veil   (4) being set back from them.   7. Shock absorber according to claim 6, characterized in that the edges of the notch (81) of the block (8) protrude circumferentially with respect to   z0 circumferential edges of the teeth (72) adjacent to the toothing (70) of the web (4).   8. Shock absorber according to any one of claims 1 to 7,   characterized in that the spacer washer (6) has notches (48) open towards the inside facing notches (58) open towards the outside carried by the hub (5) for housing second elastic means (40). and in that the third elastic means (8) are implanted between two indentations   consecutive washer spacer (6).   Shock absorber according to one of Claims 1 to 8,   characterized in that the spacer washer (6) is wedged in rotation on the hub (5) by means of pins (67) carried by the second portion (66, 166) and engaged   Each is forced into an associated opening (47) of the web (4).   Shock absorber according to one of Claims 1 to 9,   characterized in that the spacer washer (6) forms a bearing (61) interposed between the inner periphery of the first guide washer (2) and the outer periphery hub (5).   11. Shock absorber according to any one of claims 1 to 10,   characterized in that the spacer washer (6) is of moldable synthetic material.