FR2642804A1 - Torsion damping device, particularly for a motor vehicle clutch friction disc - Google Patents

Abstract

The present invention relates to torsion damping devices including guide washers 11, 11', a thin disc 4, a hub 3, a friction washer 18 belonging to first friction means 22. The washer 19 has a plurality of pegs 26 each one passing through an opening 27 provided in a guide washer 11, 11' or the thin disc. According to the invention, the pegs 26 have a size which is less than those of the corresponding openings 27 for making at least one elastically deformable tab 28 with hooks 29 which is suitable for interacting, after passing through the said opening 27, with the edge of the latter. Application: motor vehicles.

Description

 The present invention relates to torsional damping devices, in particular for clutch friction discs of motor vehicles.

 Such a damping device is described in document FR-A-2 494 795, which discloses an arrangement with two guide washers, a web and a hub mounted coaxially with respect to each other.

 In this document, the guide washers are arranged axially on either side of the web, being coaxial and angularly movable relative thereto, against first friction means and first elastic means with circumferential action, in the limits of an angular movement.

 The first friction means comprise a friction washer disposed axially between a guide washer and the web, said washer being centered relative to the axis of the assembly.

 This washer, advantageously made of synthetic material, comprises cylindrical pins each engaged in a cylindrical hole of the guide washer concerned. The opposite is possible, the pawns crossing a cylindrical hole in the web.

 In practice, the two guide washers are identical so that the other washer also has unoccupied holes.

 For mounting, the components of the friction disc are stacked axially on the same station.

 In some cases it may be advantageous to reduce the number of parts to be stacked and in particular to form sub-assemblies with a guide washer or the web to shorten the assembly time at this station.

 The object of the present invention is to solve this problem and therefore to reduce the number of pieces to be stacked in the end, while providing other advantages.

 According to the invention a device of the above-mentioned type is characterized in that the pins have a dimension smaller than those of the corresponding openings of the guide washer or of the web for providing at least one elastically deformable tab with hooks suitable for cooperating , after crossing said opening, with the edge thereof.

 Thanks to the invention it is possible to create a sub-assembly, possibly with play, guide washer, friction washers or friction-sail washers.

 Advantageously, the friction washer disposed between the other face of the web and the other guide washer can also be equipped with pins with elastically deformable legs, so that it is also possible to create a sub-assembly comprising this friction washer. , the friction lining support and the relevant guide washer.

 The assembly times during the final assembly operation can be further shortened, the said sub-assemblies being able to be produced in a place of production different from that where the final assembly takes place.

 Advantageously, the legs can be radially elastically deformable.

The description which follows illustrates by way of example the invention with reference to the accompanying drawings in which
- Figure 1 is an axial sectional view of a friction disc according to the invention;
- Figure 2 is a view along arrow II of Figure 1
- Figure 3 is a simplified view of the gear engagement means provided between the web and the hub;
- Figure 4 is an enlarged partial view, in axial section, of the first and second friction means of Figure 1
- Figure 5 is a view of said friction means alone with their associated elastic means according to arrow V in Figure 4
- Figure 6 is a partial view of a window of the web crossed by an additional tab according to the invention;
- Figure 7 is a partial view similar to Figure 1 for another alternative embodiment.

 Depending on the embodiment chosen, the clutch friction disc for motor vehicles comprises a support 1 for friction linings 2 and a hub 3, which are angularly movable relative to one another within the limits of a determined angular deflection, the support 1 and the hub 3 being coupled by two stepped torsion damping devices, one of which A, known as the pre-damper, is lower than the other B, known as the main damper.

 This disc is intended, by these friction linings 2, to be clamped between the pressure and reaction plate (not shown) of the clutch integral in rotation with the engine shaft of the vehicle, while by its hub 3 it is intended to be locked in rotation on the input shaft of the gearbox.

 For the constitution of the pre-damper A a veil 4 is mounted to be angularly movable relative to the hub 3 against second friction means 5, within the limits of an angular movement.

 Here (FIG. 3) the hub 3 has at its external periphery a flange 6 opposite the web 4.

 Means of interlocking with clearance 7, as described in document FR-A-2,560,328, are practiced partly at the internal periphery of the web 4 and partly in the flange 6. These meshing means 7 consist of a a plurality of teeth of trapezoidal shape and in a plurality of complementary notches, said teeth of the hub or of the web each penetrating with clearance in a notch of the web or of the hub.

 Second elastic means with circumferential action of low stiffness are provided, for filtration of the so-called idle noises, at the level of the interlocking means with clearance 7.

 I1 here are two coil springs 8, diametrically opposite, housed in notches 9 of the web 4 and the hub 3 with the intervention of bases 10 between the ends of the springs 8 and the edges of the notches 9 in the form of a dihedron.

 For the constitution of the main damper B of the guide washers 11, 11 'are mounted angularly movable relative to the web 4 against first elastic means 12 with circumferential action of greater stiffness than the springs 8, within the limits of '' angular travel.

 These washers 11, 11 ′ are arranged axially on either side of the web 4 while being connected with a fixed axial spacing by axial spacers 13 also serving for fixing the support 1 attached to the washer ll '.

 These spacers 13 pass through for this purpose notches 14 of the web 4, the limitation of the relative clearance between the web 4 and the washers 11, 11 ′ being able to be effected by cooperation of the spacers 13 with the edges of the notches 14 or by coming with contiguous turns of the springs 12.

 The springs 12 are housed in windows 15, 16, facing each other, respectively of the guide washers 11, 11 'and of the web 4.

 The washers 11 freely surround the hub 3, no backlash engagement means being provided, while the web 4 surrounds the hub 3 with intervention of the backlash engagement means 7.

 An annular bearing 17, of generally L-shaped section, is interposed between the disc 1, doubling the guide washer 11 ', and the web 4 by transversely forming a spacer washer.

 This bearing is also inserted radially between the internal periphery of the washer 11 'and the external periphery of the hub 3.

 I1 is linked in rotation to the washer 11 ′, its annular axial part having bosses engaged in complementary notches of the washer 11.

 Between the other guide washer 11 and the web 4 are interposed friction washers 18,19 and associated elastic means for setting the friction 20,21, here in the form of Belleville tab washers.

 The washer 20 is supported on the washer 11 and urges the washer 18 in the direction of the web 4 for tightening the bearing 17 between the support 1 and the web 4.

The washer 21 is supported on the washer ll and urges the washer 19 in the direction of the flange 6, for tightening the bearing 17 between the washer 11 'and the flange 6 (the support 1 extending radially beyond the flange 6 ),
The guide washers are therefore angularly movable relative to the web 4 against first friction means 22 comprising the washers 18,20 and the bearing 17. Similarly the hub 3 is angularly movable relative to the web 4 to the against second friction means 5 comprising the washers 19,21 and the bearing 17; the two friction means 22.5 being arranged radially one above the other, the washers 18.20 surrounding the washers 19.21.

 Stop means 24 are provided between the web 4 and / or one of the friction washers 18,19 and the guide washer 11,11 'concerned.

 Axial retaining means 25 are provided between the two said friction washers 18,19.

 Here the stop means consist of latching means. More specifically, the washer 18, advantageously made of synthetic material such as the washer 19 and the bearing 17, has in one piece a plurality of lugs in the form of axially projecting pins 26, regularly distributed circularly, each passing through a cylindrical opening 27 of the washer. guide for connection in rotation therewith.

 According to the invention the pins 26 have a size smaller than that of the corresponding openings 27 for the provision of at least one elastically deformable tab 28 with hooks 29, suitable for being hooked after crossing the opening 27 on the guide washer-ll concerned or the veil 4.

 Here the upper part of the pins 26 is interrupted for the provision of radially elastically deformable legs 28, narrower and longer than the pins 26, the size of which is smaller than that of the openings 27 as described below.

 The free end of the tabs 28 is provided with a hook 29, with a rounded end 30 facilitating threading into the opening 27, said hook 29 being directed radially opposite the axis of the assembly for formation of 'a shoulder.

 Each cylindrical pin 26 has an oblong shape with two rectilinear edges connected by a rounded bottom (FIG. 5), and has in its lower part a shape complementary to that of the opening 27.

 As can be seen in FIG. 2, it is the tab 28, thanks to its hook 29, which is intended to cooperate with the upper radial edge of the opening 27, said edge being rectilinear and wider than the orientation tab 28 axial, so that a lateral contact between the tab 28 and the lateral edges of the opening 27 is not to be feared (FIG. 2).

 It will be noted that an opening 31 exists between the lug 28 and the upper edge of the pins 26, said pins 26 and lugs 28 each being made in favor of an ear 32 which the washer 18 has at its outer periphery, the lug 28 being longer than pawn 26.

 The opening 31 can be non-opening (FIG. 1) or opening (FIG. 4) to give more flexibility to the tabs 28.

 Here four ears 32 and four pairs of pins 26 and legs 28 are provided, the openings 31 being open at the phase of the ears 32 facing the web 4.

 Of course, two lateral tabs could have been provided, each intended to cooperate with one of the lateral edges of the opening 27, but this is less advantageous than the arrangement with radial tabs 28 which makes it possible to conserve the maximum of material for the pins 26, for better contact with the opening 27.

 Furthermore, no interference is to be feared with the clutch diaphragm.

 The Belleville washers 21, 22 are mounted head to tail and are supported on the washers 18, 19 by being centered respectively by the pins 26 and an annular axial return 33 which the washer 19 has at its internal periphery.

 This return 33 has locally bosses 34 for cooperation each with a complementary notch of the washer 11 and connection en.rotation with the latter.

 As will be understood, the washers 20, 21 allow a taring of the frictions.

 Alternatively it may be wavy washers.

 The axial retaining means 25 here comprise a radially oriented shoulder 36 forming on the internal periphery of the washer 18, said shoulder 36 being turned towards the guide washer II for cooperation with a bearing 37 belonging to the external periphery of the washer 19 , said bearing surface 37 being formed on the face of the washer 19 facing away from the washer 11.

 Here the axial retaining means 25 are divided, the bearing surface 37 belonging to lugs 38 of the washer 19, projecting radially with respect to the external periphery of said washer 19 and each engaged in a complementary notch 39 provided at the internal periphery of the washer 18, said notches being closed by the shoulders 36 (Figure 4).

 Of course, the reverse arrangement is possible, the edge of the washer 18 having tabs each engaged in a notch formed at the outer periphery of the washer 19, the retaining shoulder can in this case be produced in the form of tabs, extending the face of the washer 18 facing the web 4, projecting radially and alternating with the previous tabs, being longer than these and axially offset.

 The scope can be created by closing the groove of the washer 19 at its end closest to the rondelle.ll for cooperation with the tabs of the washer 18 engaged in said grooves.

 As a variant, the shoulder may be continuous and connected to each other by the tabs projecting from them.

 As will have been understood, a connection in rotation and a prepositioning of the washer 19 relative to the washer 18 is made possible by this arrangement, the shape of the washer 19 being dictated by considerations of standardization, the bosses 34 being able to very well not to exist.

 Thus it is possible to create a unitary washer sub-assembly 11, 19, 18, 20, 21.

 To do this, the washer 21 is stacked first, then the washer 19, then the washer 20, and finally the washer 18, the tabs 28 of which retract radially in the direction of the axis of the assembly, thanks to the opening 31, to then be hooked, by their hooks 29 and under the action of the washers 20, 21, on the opposite face of the guide washer 11.

 Referring to FIG. 4, it is understood, before assembly of the web 4 and the hub 3, that the washer 19 is retained axially by the washer 18, the latter engaging by its shoulder 36 with the bearing 37.

 After final positioning of the spacers 13, the set of washers 18, 19 is compressed and a clearance remains between the washer 19 and the shoulder 36 As well as between the hook 29 and the washer 11.

 Of course, clearances can be provided in the stop means 24 and in the axial retaining means 25, the position of the hooks 29 being such that the pins 26 cannot escape from the openings 27 and take account of the wear of the washer 18.

 It will be appreciated according to an important characteristic of the invention, the guide washers 11, 11 'being identical to each other, that the bearing 17 may also have pins 26 and lugs 28 for engagement in the openings 27 of the washer 11'.

 Thanks to this arrangement it is possible to form a sub-assembly of guide washers 11 'support 1, the balusters 13 being mounted during the final assembly.

 As a reminder, it will be recalled, when the support moves angularly relative to the hub 3, that initially the guide washers 11, 11 ′ form a block with the web 4 containing the stiffness of the springs 12 relative to the springs 8, until the play of the play engagement means 7 is canceled, then in a second step the guide washers 11, 11 ′ move angularly relative to the web 4 against the springs 12.

 Thus, at first, the washer 19 intervenes, while the washer 18 comes into action after the web 4 is secured in rotation with the hub 3.

 Of course, the present invention is not limited to the embodiments described.

 In particular, the axial retaining means 25 may consist of complementary conical bearing surfaces which the washers 18 and 19 have respectively at their internal periphery and at their external periphery.

As part of a provision according to the document
FR-A-2 611 245, the shoulder 36 may belong to the washer 19 as well as the abutment means 24, when the friction washer 18 crosses the web 4, abutment means then acting between the end of said legs and the face of the web turned opposite to said friction washer 18. These abutment means may comprise elastically deformable lugs with hooks similar to lugs 28, the shoulder then extending in the direction of the axis of the assembly .

 In this case, the abutment means according to the invention can be provided at the level of the friction washer 19, as is the case in the figures described above, the lugs 28 being associated with the bosses 34 with the guide washer 11.

 The legs 28 may be separate from the pins 26, additional openings then being provided in the washers 11, 11 '.

 Additional tabs 28 ′, directed axially in the opposite direction to the tabs 28 can pass through the web 4, for example through the windows 15 (FIG. 6) formed for this purpose with the guide washer ll. In this case the internal edge of the window is indented at 100, to allow the passage to circumferential play of the tab 28 ', the hook 29' of which is directed towards the axis of the assembly and the formation of additional stop means.

 Thanks to the additional tabs 28 ′, the web 4 can be clipped onto the guide washer sub-assembly 11 and friction means 22.5.

 Similarly in FIG. 7, a sail sub-assembly 4 friction means 22.5 can be formed by reversing the direction of the washers 18 and -19.

 In this figure, the washer 18 crosses openings 27 of the web, the stop means 24 acting between the web 4 and the washer 18 with legs 28 and pins 26.

 The washer 20 rests on the web 4 and urges the washer 18 in contact with the washer 11.

 The washer 21 is supported on the flange 6 and urges the washer 19 into contact with the washer 11.

 It will be noted, that the washer 21 being continuous, that the latter cannot escape from the sub-assembly 4,22,5, since the teeth of the web 4, belonging to the meshing means 7, retain the washer 21.

 It will also be noted that the retaining shoulder of the washer 18 faces the web 4 and that said washer 18 can be provided with additional tabs, similar to the tabs 28, for hooking onto the washer 11.

 For the record, it should be noted that the reference 119 represents a bearing and the reference 116 a spacer washer.

 Of course, the elastic means of low stiffness 8 can belong to a pre-damper with guide washers and web disposed axially between the web 4 and one of the guide washers 11, 11 'as described in the above-mentioned document FR-A- 2,611,245 and in application DE-A-38 10,922.

 The veil 4 can be split as described in document FR-A-2 566 497.

 This veil can be secured to the hub as described in the above-mentioned document FR-A-2 494 795, the washers 19, 21 no longer existing in this case.

 Finally, the invention is applicable to a torsion damper devoid of support 1, for example one of the guide washers 11, 11 'which can be directly fixed to a flywheel secured to the motor shaft, the hub being coupled to the input shaft of a gearbox.

Claims (8)

 1) Torsion damping device, in particular for a clutch friction disc of motor vehicles, comprising two guide washers (11, 11 ') arranged axially on either side of at least one web (4) being coaxial and angularly movable with respect thereto against first friction means (22) and first elastic means with circumferential action, within the limits of an angular movement, a hub (3) surrounded by the web (4 ) and the guide washers (il, 11 '), said first friction means (22) comprising a friction washer (18) disposed axially between one of the guide washers (11,11') and the web (4 ) being centered relative to the axis of the assembly, said washer (18) of the first friction device (22) comprising cylindrical pins (26) each engaged in cylindrical holes (27) of the web (4) or of the relevant guide washer, characterized in that the pins (26) have a dimension smaller than that of said openings (27) for providing at least one elastically deformable tab (28) with hooks (29) capable of cooperating after crossing of said opening (27) with the edge thereof.  2) Device according to claim 1, characterized in that the legs (28) are longer than the pins (26) being narrower than these.  3) Device according to claim 1 or 2, characterized in that said tabs (28) are radially elastically deformable.  4) Device according to claim 3, characterized in that the upper part of the pins is (26) is interrupted to spare the legs (28).  5) Device according to claim 4, characterized in that the tab (28) is separated from its pin (26) by a slot (31).  6) Device according to claim 5, characterized in that the hooks (29) are directed in the direction opposite to the axis of the assembly for cooperation with the upper radial edge of the opening (27).  7) Device according to any one of the preceding claims, in which the two guide washers (11,11 ') are identical and in which a support (1) is attached to the other guide washer (11,11') and each have an opening (27), characterized in that a spacer washer (17) being interposed between the web (4) and the other guide washer (11 '), said spacer washer (17) has pins ( 26) and lugs (28) for engagement in the openings (27) and formation of a guide washer (11 ') and support (1) sub-assembly.  8) Device according to claim 7, characterized in that additional tabs (28 ') are provided between the other of said web elements (4) and guide washer not affected by the tabs (28).