FR2660036A1 - Double damping flywheel, particularly for motor vehicle - Google Patents

Abstract

The present invention relates to a double damping flywheel, including two masses (1, 10), elastic means (20, 22) located inside a first cavity (30), a viscous arrangement (60) comprising a second cavity (50), and a bearing (9) interposed radially between the said masses (1, 10), in which the second mass includes a reaction plate (11) and a disc (33). According to the invention, the said plate (11) is provided with axial projections (40) extending radially between the first (30) and the second (50) cavity, the disc (33) is shaped at the said projections (40) for interfitting, possibly with clearance, with the latter, the second mass (10) is axially wedged on to the first one (1) via the bearing (9), and the said projections (40) come out of the plate (11) and constitute centring means for the arrangement (60). Application: motor vehicles.

Description

 The present invention relates to a double damping flywheel, in particular for a motor vehicle, of the type comprising two coaxial masses mounted to rotate relative to one another, against elastic means and an arrangement with viscous damping.

Such a double flywheel is described in the document
FR-A-2 626 326.

 In it the elastic means are housed inside a first sealed cavity, while the viscous damping arrangement is located radially below the first cavity by being mechanically interposed between the two masses.

 Said arrangement comprises a second sealed cavity filled with a second fluid distinct from the first and is wedged axially on one of the masses.

 The arrangement also comprises two closure parts integral with an external support element.

 One of the closing parts is connected by screwing or riveting to a reaction plate belonging to the second mass of the double flywheel, mounted on the first mass by means of a bearing.

 I1 follows that this closure part is the object of stress, which under very severe conditions can be harmful to the sealing of the second cavity.

 I1 is all the more so that the rivets or the screws are not all rigorously disposed on the same circumference due to manufacturing tolerances, which further increases said stresses.

 In addition it has at least one thicker area.

 The object of the present invention is to overcome these drawbacks and therefore to reduce the stresses at the level of the viscous arrangement cavity, while simplifying the manufacture of the double flywheel, and providing other advantages.

 According to the invention a double flywheel of the type indicated above, in which a web penetrating into the first cavity, for interference with the elastic means, is linked in rotation, possibly with play, with the viscous arrangement, is characterized in that the reaction plate is provided with axial protrusions extending radially between the first and the second cavity, in that the web is shaped at the level of said protuberances for interlocking, possibly with play, with these, in that the second mass is wedged axially on the first mass via the bearing, and in that said axial protuberances come directly from the reaction plate and constitute centering means for the arrangement with viscous damping.

 Thanks to the invention, the stresses at the level of the second cavity are minimized and the closure pieces do not need to be excessively thickened.

 In fact, thanks to the protuberances, the viscous arrangement is well centered and does not need to be fixed to the reaction plate, which makes it possible to reduce the stresses and improves the seal.

 In addition, the closure parts are simple and can be identical to each other. The axial size of the double flywheel can thus be reduced.

 In addition the protrusions, advantageously from a sleeve, allow a good seal by forming narrow passages.

The appended description illustrates the invention with reference to the appended drawings in which
- Figure 1 is a partial half front view of the double flywheel showing the interior of the cavities that it comprises
- Figure 2 is an axial sectional view along broken line AA of Figure 1
- Figure 3 is a half-view in axial section on a smaller scale for a second embodiment.

 The double shock-absorbing flywheel for a motor vehicle, illustrated in these figures, comprises two coaxial masses 1.10 rotatably mounted relative to one another, against elastic means 20 and an arrangement with viscous damping 60 .

 More precisely in these figures, we see at 1 one of the masses of the double damping flywheel, said mass 1 comprising a housing 3 closed by a cover 5 and a central hub 8, secured together at the nose of the crankshaft of the internal combustion engine of the vehicle by a plurality of screws 2 passing through openings made in the hub 8 and the housing 3.

 The housing 3 is secured, by virtue of its bottom, to the hub 8 by screws 61 and carries, by its peripheral rim of axial orientation, a starter ring 4.

 The cover 5 is fixed by rivets 6 to said hollow housing 3, which is here of annular shape like the cover 5.

 Guide washers 31, 32, here in the form of a plurality of blocks, are fixed by watertight riveting to the housing 3, the blocks 32 being fixed by rivets 37 to the bottom of the housing, while the blocks 31 are fixed by rivets 36 to said bottom, with the intervention of a spacer 35 between said blocks 31 and an annular wall of axial orientation 39 of the housing 3.

 This spacer 35 carries circumferentially at each of its ends blocks 38 of elastomeric material.

 A web 33, integral in rotation, possibly with play, with the second mass 10, is disposed axially between the guide washers 31, 32.

 I1 is provided with radial arms 34 for support on elastic means 20, here coil springs with circumferential action, functionally interposed between the two masses 1.10.

 These springs 20 are mounted by means of pivoting bases 21 between two consecutive blocks 32, and two consecutive blocks 31, knowing that the blocks 31, 32 are arranged opposite one another.

 These bases are adapted to interfere with the arms 34 provided with notches for this purpose.

 The second mass 10 comprises an annular plate 11 forming the reaction plate of a clutch, on which is adapted to come into contact with the friction disc (not shown) of the clutch integral in rotation with the input shaft of the gearbox.

 A bearing 9 is interposed radially between the plate 11 and the hub 8.

 It can be an anti-friction bearing or a bearing, as in Figures 1 and 2.

 This bearing 9 is wedged axially on the hub 8, on the one hand, by means of a shoulder, which has said hub 8, and on the other hand, by means of a washer 12, in contact with the free end of said hub 8 and crossed by the fixing screws 2.

 The bearing 9 is fixed axially on the reaction plate 11 by means of a shoulder 14 of said reaction plate and a washer 13 disposed generally radially in alignment with the washer 12 above the latter.

 This washer 13 is fixed by rivets 15 to the plate 11.

 The elastic means 20 are arranged inside a first cavity 30 filled with a first fluid and delimited by the two masses 1 and 10.

 More precisely, this cavity 20 is delimited for the most part by the first mass 1, in particular by the housing 3, the flange 5, the wall 39, and the spacer 35.

 It is also delimited by the veil 33, the radial arms 34 of which penetrate inside the latter.

 This cavity 30 is partially filled here with a lubricating fluid for the springs 20, in the form of grease.

 The double flywheel also has a viscous damping arrangement 60 mechanically interposed between the two masses 1 and 10.

 This arrangement 60 comprises a second sealed cavity 50 filled with a second fluid distinct from the first fluid and delimited by said masses 1 and 10.

 This second cavity 50 is located radially below the first cavity 30.

 Of course, seals have been provided for the cavities 30.50 represented by dark areas in FIG. 2 and of which only one is identified by 63.

 The viscous damping arrangement 60 is integral with the annular web 33 and is arranged axially between the bottom of the housing 3 and the reaction plate 11.

 This second cavity 50 is delimited by two discs 51, 52, or closing parts, annular and identical, arranged on either side of the web 33 forming a spacer and attached to it by riveting with intervention of the centering pins, as visible respectively in the upper part and in the lower part of figure 2.

 This cavity 50 is also delimited by the hub 8 which carries a projecting flange 53 interposed axially between the two parts 51 and 52.

 This flange 53 constitutes an external support element carrying teeth 55 of radial orientation penetrating inside the cavity 50 in the direction opposite to the axis of the assembly.

 The veil 33 forms an external support element and carries on its internal periphery teeth 54, of reverse radial orientation of the teeth 55.

 The teeth 54 alternate with the teeth 55 and calibrated passages exist in particular between said teeth 54,55 and said parts 51,52.

 As a variant, the teeth may be omitted, and in this case, the flange 53 is in the form of a disc extending to the web 33 and is allowed to wrestle with respect to the closure parts 51, 52 with the formation of narrow passages. between said parts 51.52.

 This cavity 50 is partially filled here with a second high viscosity fluid, such as silicone.

 As is known, the viscous arrangement is admitted to have its effects for low revs, in particular when the engine is started and stopped, when the resonant frequency is passed below the idle speed of the engine. engine.

 According to the invention, a double flywheel of the type indicated above is characterized in that the reaction plate 11 is provided with axial protrusions 40 extending radially between the first 30 and the second 50 cavity, in that the web 33 is shaped at the level of said protuberances 40 for interlocking, possibly with clearance, with these, in that the second mass 10 is wedged axially on the first mass 1 via the bearing 9, and in that said protuberances 40 come directly of the reaction plate 11 and constitute centering means for the viscous damping arrangement.

 As can be seen in FIG. 2, these probutances 40 here form tenons and alternate with mortises 41, so that the reaction plate 11 has, at its level, the shape of an annular comb.

 More precisely, the tenons and mortises are made at the end of a cylindrical sleeve 43 and are therefore in the shape of an arc of a circle.

 The veil 33, linked in rotation, possibly with play, to the arrangement 60 and to the plate 11, has complementary notches to cooperate with the tenons 40.

 These notches are delimited in particular by the arms 34, radial lugs 70 of lesser height than the arms 34, as well as by the external periphery of the web 33.

 As can be seen in FIG. 1, there is a circumferential alternation of legs 70 and arms 34, the legs 70 being intended to cooperate with the spacer 35.

 The internal periphery of the protrusions 40 co-operates in centering with the external periphery of the disks 51 and 52 of the arrangement 60.

 These protrusions have a small thickness because they come directly from the plate 11, and extend in axial clearance relative to the bottom of the housing 3, the end of said protrusions cooperating with the wall 39, for the formation of narrow passages.

 The sleeve 43 also cooperates with the cover 5 and the guide washer 31 to form narrow passages.

 Thus, the external periphery of the protrusions 40 and of the sleeve 43 also has a sealing function, so that a seal can be saved between the cover 5 and the sleeve 43.

 Of course, one can provide such a seal or a baffle.

 It will be noted that these protrusions 40 extend radially above the bearing 9.

 As is evident from the description and the drawings, the axial size of the double flywheel is reduced and it is possible to mount in the housing 3 the various constituents by stacking and to bring back by interlocking the tray of final reaction 11.

 The small thickness of the protrusions 40 makes it possible, as visible in FIG. 3, to gain space radially and therefore to mount, for example, a second series of springs 22 inside the first series of springs 20, or to increase the layout size 60.

 Of course the present invention is not limited to the embodiments described, in particular the washer 13 can be mounted not on the side opposite to the arrangement 60, but adjacent thereto, the shoulder 114 of the plate 11 is then removed from the viscous arrangement 60.

 The internal support element 53 can be mounted with clearance relative to the hub 8 for example by a set of grooves.

 The veil 33 can also be integral only in rotation with the arrangement 60 and be fitted by interlocking thereon.

 Similarly, the protrusions 40 can mesh with play and intervention of damping elements made of elastic material.

 In all cases, the axial protrusions of the plate 11 are intended to cooperate with the counterprofiles of the web 33.

Claims (7)

 1) Double damping flywheel, in particular for a motor vehicle, of the type comprising two coaxial masses (1,10) rotatably mounted relative to one another, against elastic means (20,22) arranged at the interior of a first sealed cavity (30) and of a viscous damping arrangement (60) comprising a second sealed cavity (50), in which a bearing (9) is interposed radially between said masses (1,10), and in which one of the masses, called the second mass, comprises a reaction plate (11) integral in rotation, optionally with play, with a veil (33) penetrating inside the first cavity (30), characterized in that said reaction plate (11) is provided with axial protrusions (40) extending radially between the first (30) and the second (50) cavity, in that the web (33) is shaped at the level of said protrusions ( 40) for interlocking, possibly with play, with these, in that the second the mass (10) is wedged axially on the first mass (1), by means of the bearing (9), and in that said axial protuberances (40) come directly from the reaction plate (11) and constitute means centering device for the viscous damping arrangement (60).  2) Double flywheel according to claim 1, characterized in that the protrusions (40) form tenons and alternate with mortises (41).  3) Double flywheel according to claim 2, characterized in that the tenons (40) and the mortises (41) are formed at the end of a cylindrical sleeve (43).  4) Double flywheel according to any one of claims 1 to 3, characterized in that the web (33) has complementary notches to cooperate with said protuberances (40).  5) Double flywheel according to claim 4, characterized in that the notches of the veil are delimited by radial arms (34) of the veil (33), penetrating the first cavity (30), and by radial tabs (70) of the veil (33) of lesser height, with circumferential alternation of said legs (70) and said arms (34).  6) Double flywheel according to any one of the preceding claims, in which the viscous damping arrangement (60) comprises two closing parts (51,52) in the form of discs, characterized in that the protuberances (40) are clean to cooperate in centering with the outer periphery of said parts (51,52).  7) Double flywheel according to any one of claims 3 to 6, in which the first mass (1) comprises a cover (5) attached to a housing (3) for delimitation of the first cavity (30), characterized in that the sleeve (43) of the reaction plate (11) defines with said cover (5) a narrow passage.