FR2734331A1 - Damped flywheel, esp. for motor vehicle - Google Patents

Abstract

The flywheel comprises two coaxial members (1, 2) able to move relative to one another and counter to a resilient damper (3) with at least one spring (31) which is pivoted to both members. The position of the spring varies with the relative movement of the two coaxial members, which are linked by a central bearing (14). The first of the two coaxial members has a central sleeve (13) on which the bearing and the second member are mounted, and the spring is connected to the inner edge of one member and the outer edge of the other, being set in an aperture (16) in the first member's disc which is also used for ventilation.

Description

 The present invention relates to a damping flywheel, in particular for a motor vehicle, of the kind comprising two coaxial masses mounted movable relative to one another against an elastic damping device comprising at least one elastic member acting between said masses.

Such a damping flywheel, usually called a double damping flywheel, is described for example in the documents FR-A-2 556 800, FR-A-2 571 461,
FR-A-2 553 858.

 As is known, in a damping flywheel for a motor vehicle, one of the masses is locked in rotation on the crankshaft of the internal combustion engine of the vehicle, while the other mass is locked in rotation, via a friction clutch on the input shaft of the gearbox.

This flywheel is designed to filter vibrations that arise in the kinematic chain from the engine to the wheel shafts.

 Thus in this system equipped with the damping flywheel, the resonant frequency is reported below the idle speed of the internal combustion engine, so that when the engine is started and stopped, the resonant frequency is passed.

 At normal vehicle operating speed, the resonance phenomena do not exist in the operating speed range of the heat engine. However, various arrangements must be made to attenuate the resonance phenomena when the motor vehicle engine is started and stopped.

 Thus in document FR-A-2 571 461, provision has been made with a torque limiter, which allows unlimited rotation of one mass relative to the other when passing through the resonant frequency.

 This torque limiter must be calculated to transmit the maximum torque of the engine and not slip beyond said maximum torque. As a result, a safety factor must be provided so that the setting of the limiter is not optimum.

 In document FR-A-2 556 800, provision has been made to short-circuit the elastic device of the damping flywheel and to establish a temporary temporary connection for securing the two masses in rotation when the vehicle is started.

 This is achieved for example using a starter pinion which, when the internal combustion engine is launched, engages both in the teeth provided correspondingly in each of the masses.

 This arrangement is not entirely satisfactory because it requires in particular to modify the starter of the vehicle. In addition, there is a problem of phasing between the teeth of each of the masses.

 In document FR-A-2 553 848 provision has been made for temporary locking of the centrifugal type between the two masses when the vehicle is started.

 This solution is also not entirely satisfactory because this centrifugal locking can get stuck. In addition, it requires a large number of parts.

 Furthermore, in the above-mentioned documents, the elastic members usually consist of helical compression springs acting circumferentially between the two masses.

 These springs, under the action of centrifugal force, can rub against, for example, a skirt belonging to one of the masses so that friction and spring wear can occur.

These springs can even get stuck in some cases.

 Usually provision is made to lubricate these springs by mounting them for example in a cavity delimited for the most part by one of the masses and filled at least in part with grease. It is also possible to equip the springs with anti-wear parts, such as pads, parts in the form of a chute.

 In addition, the torsional stiffness of the device is constant and in a given space the torque transmission capacity is limited.

 Usually a hysteresis friction device is also provided between the two masses with a friction washer acting in a delayed manner to dampen the resonance phenomena, but the adjustment of which is not easy to carry out.

 In addition, all of these provisions can give rise to significant friction in the area of the idling speed of the internal combustion engine.

 The object of the present invention is to overcome these drawbacks and therefore to create, in a simple and economical manner, a new damping flywheel having an increased torque capacity, not very sensitive to starting and stopping the engine of the vehicle, while being d 'a reduced cost and by having an elastic damping device provided with at least one elastic member with reduced friction which does not require lubrication.

 According to the invention, a damping flywheel of the above-mentioned type is characterized in that the elastic member of the elastic damping device is articulated on one and the other of said masses and in that said elastic member intervenes, radially between said masses for the rest position of the damping flywheel, so that said elastic member occupies a radial rest position and inclined working positions.

 Thanks to the invention, the damping flywheel can transmit higher torques, while having an elastic member with reduced parasitic friction due to its articulated mounting.

The examination of the different situations of use of the heat engine makes it possible to highlight the advantages brought by the device object of the invention
- when the engine is idling, gearbox in neutral, the low stiffness associated with the low friction of the device ensures optimal filtration
- when the engine is engaged and whatever its speed and the transmitted torque, the evolutionary characteristic of the torsional stiffness allows the transmission of the torque while ensuring an optimal filtration thanks to a level of stiffness which although variable is sufficiently low and reduced friction
- in the starting and stopping phases of the heat engine, characterized by a very low level of transmitted torque, the very low stiffness characteristic which is continuously variable with the clearance naturally allows the resonance phenomenon to be very greatly attenuated (the resonant frequency becomes variable with the travel) in the absence of any additional friction or locking device.

 The stiffness of this elastic damping device is therefore variable with its clearance, in particular thanks to its articulated mounting.

 In general, the damping flywheel according to the invention is of economical construction and does not require greasing the springs.

 In one embodiment, the elastic member can be mounted directly at articulation on the two masses. As a variant, the elastic member can be mounted with articulation on the two masses by means of tie rods, preferably mounted head to tail.

 The articulation can be done using pins. The axes associated with the second mass, forming the reaction plate of a clutch, can be mounted between two consecutive holes provided for the passage of a tool intended for the screwing of the screws fixing the first mass to the crankshaft of the engine.

 As a variant, said axes of the second mass can be installed in favor of said holes.

 The second mass can be pivotally mounted on the first mass using bearing means, such as a bearing, acting either between the internal periphery of the second mass and the external periphery of a hub of the first mass, or between the external periphery of the second mass and a part carried by the external periphery of the first mass.

The following description illustrates the invention with reference to the accompanying drawings in which
- Figure 1 is an axial sectional view of a damping flywheel according to the invention
- Figure 2 is a partial view along arrow 2 in Figure 1
- Figure 3 is a sectional view along line 3-3 of Figure 2
- Figures 4 and 5 are views showing the tie rods
- Figure 6 is a schematic view of the elastic damping device occurring between the two masses
- Figure 7 is a diagram showing the characteristic curve of the damping flywheel according to the invention
- Figure 8 is a partial view in axial section for another embodiment
- Figure 9 is a partial view in axial section showing the center of the double flywheel for yet another embodiment
- Figure 10 is a partial view for another example of an elastic member
- Figure 11 is a view along arrow 10 in Figure 10
- Figures 12,13 and 14 are views similar to Figure 11 for yet other embodiments
- Figure 15 is a view along arrow 15 of Figure 14
- Figure 16 is a view similar to Figure 11 for yet another embodiment
- Figures 17 and 18 are views similar to Figures 10 and 11 for yet other embodiments.

 In FIG. 1, there is shown a damping flywheel for a motor vehicle comprising two coaxial masses 1,2 mounted movable relative to one another against an elastic damping device 3 comprising at least one member elastic 31, 32, 33 intervening between the two masses 1 and 2. The second mass 2 is mounted, swiveling on the first mass 1 using bearing means.

 Here the first mass 1 generally comprises a plate 11 carrying at its outer periphery a starter ring 12, suitable for being driven by the starter of the motor vehicle.

 Here the mass 1 is driven by the internal combustion engine of the motor vehicle by being fixed on the crankshaft 100 of said engine using screws 101 and the plate 11 has a sleeve 13 axially oriented centrally. This sleeve 13, here in one piece with the plate 11, carries a bearing 14 radially interposed between the external periphery of the sleeve 13 and the internal periphery of the mass 2.

 Here, the bearing 14 consists of a ball bearing axially wedged on the plate 2 and on the hub 13 by means of shoulders formed on said parts 14.2 and of circlips engaged in grooves made in said parts 14.2.

 The mass 2 has from place to place holes 27 for passage of a tool allowing the screwing of the screws 101 and the fixing of the first mass 1 to the crankshaft 100.

 The second mass 2 forms the reaction plate of a friction clutch comprising a pressure plate 21, a diaphragm 22, a cover 23 and a friction disc 25.

 Here the cover 23 has a shape of a hollow plate with a centrally perforated bottom and is fixed by its radial rim using screws on the reaction plate 2. The diaphragm 22 is pivotally mounted on the cover using small columns, one of which is visible in the lower part of Figure 1.

 This diaphragm 22 rests on the pressure plate 21 and urges it in the direction of the reaction plate 2 for tightening the friction linings, which the disc 25 carries at its outer periphery, between said pressure and reaction plates 2 .

 The disc 25 is coupled to a central hub (not visible) locked in rotation on the input shaft of the gearbox.

 The pressure plate 21 is linked in rotation to the cover 23 by being mounted to move axially relative to the latter, in a manner known per se, using tangential tongues 24.

 Normally the clutch is engaged and as mentioned above the friction linings of the disc 25 are clamped between the plates 2,21.

 To disengage the clutch, it is necessary to act here by pushing, using a clutch release bearing 26 on the end of the fingers of the diaphragm 22 to rotate the latter so as to cancel the load exerted by the diaphragm 22 on the pressure plate 21 then returned towards the bottom of the cover 23 by the tangential tabs 24.

 Thus the first mass is locked in rotation on the crankshaft of the internal combustion engine, while the second mass 2 is locked in rotation on the input shaft of the gearbox via a friction clutch 2 , 21 to 25.

 This being recalled, according to the invention, a damping flywheel of the above-mentioned type is characterized in that the elastic member 31, 32, 33 of the elastic damping device is mounted with articulation on both of said masses 1,2, and in that said elastic member intervenes radially between said masses for the rest position of the damping flywheel, so that said elastic member occupies a radial rest position and inclined working positions.

 Here, said elastic member is mounted articulated on the two masses 1,2 by means of tie rods 4,5 better visible in FIGS. 4 and 5. The tie rods are in the image of one another.

 More precisely in FIGS. 1 to 5, three elastic members 31, 32, 33, in the form of identical coil springs, are provided by tie rods 4.5.

 Four crews of tie rods 4,5 and springs 31,32,33 are regularly distributed circularly. Two of these are shown in Figure 2.

 To do this for each crew 4,5,31,32,33 mentioned above, the plate 11 has windows 16 and recesses 17. The recesses 17 are made at the outer periphery of the plate 11 of the mass 1 opposite the mass 2 , while the windows 16 extend from the internal periphery of the plate 11, radially beyond the screws 101 and up to the vicinity of said recesses 17.

 The recesses 17 and the windows 16 allow the mounting of the coil springs 31 to 33. Here the tie rods 4 and 5 are in the form of tridents. They are produced by cutting with a press while being made of sheet metal.

 Of course, other arrangements are provided depending on the applications. The tie rods can have one tooth, five teeth, etc. In this case a spring, five springs etc. are provided. Advantageously, provision is made for an odd number of teeth and springs.

 Here the tie rod 4 has a base 44 with a curved dorsal face and three teeth 41,42,43 which are connected in one piece to the base 44. This tie rod 4 has a symmetrical shape just like the tie rod 5.

 The teeth 41 and 42 are in the image of one another and each have a chamfered free end.

These teeth 41 and 42 symmetrically frame the longer central tooth 43, the free end of which is widened and has a hole 46 for mounting a hinge pin 7 described below. The central tooth 43 is longer than the teeth 41 and 42. Between the teeth 42 and 43, the base 44 is stepped with the formation of shoulders 47, 48 offset axially with respect to each other.

 Between the teeth 41 and 43, the base 44 has a shape symmetrical with respect to that which it has between the teeth 43 and 42 so that said base is stepped at this level.

 The tie rod 5, similar in shape to that of the tie rod 4, has a base 54 with a domed dorsal face, but this dorsal face is indented or hollowed out centrally at 55 for passage of the hinge pin 7 described below. Three teeth 51 to 53 are connected in one piece to the base 54.

 The teeth 51 and 52 are in the image of one another and have a free beveled end. The teeth 51 and 52 symmetrically frame the central tooth 53.

 This central tooth is longer than the teeth 51 and 52 and has a free open end with a hole 56 for mounting on a hinge pin 6 described below.

 As for the tie rods 4, the base 54 of the tie rod 5 is stepped between the teeth 52.53 and between the teeth 53.51 and this symmetrically with the formation of shoulders 57.58 offset axially relative to the other.

 It will be noted that the shoulder 48 adjacent to the central tooth 43 corresponds to a recess, while for the tie 5 the recess corresponds to the shoulder 57 farthest from the central tooth 53. This thus optimally occupies the space between the two bases 44, 54 of the tie rods with good support of the springs.

 According to one characteristic, the tie rods 4 and 5 are mounted back to back and their teeth 41,42,43-51,52,53 are capable of coming into sliding contact with one another.

 To reduce friction, provision is made to interpose a coating 8 made of a material with a low coefficient of friction, such as "Teflon", between the two tie rods 4 and 5 to facilitate the relative movement between the two tie rods 4,5.

 These tie rods are mounted inside guides 34, 35, 36 of tubular shape. Thus, the external faces of the tie rods 4 and 5 are suitable for rubbing against the internal faces of the guides 34, 35, 36, here of tubular shape with rectangular internal section, just like the teeth of the tie rods 4 and 5.

 The guides 34, 35, 36 are advantageously made of synthetic material with a low coefficient of friction and are sized according to the teeth of the tie rods 4 and 5.

 Each guide 34, 35, 36 has two diametrically opposed guide ribs 40, 50 coming from the longitudinal edges of the guides.

 As will be understood and it is evident from the drawings, the coil springs 31, 32, 33 are mounted respectively on the guides 36, 34, 35 while being threaded thereon in particular on the ribs 40, 50, the lateral edges of the guides 34, 35, 36 being rounded to match the internal periphery of said springs (FIG. 3).

 It will be appreciated that, thanks to the shoulders 47, 48, 57, 58, interference between two consecutive coil springs 31, 32, 33 is avoided. The risks of friction are therefore minimized.

 Indeed, the central spring 52 is supported at one of its ends on the shoulders 58 of the tie rod 5 and at the other of its ends on the hollow shoulders 48 of the tie rod 4, while the spring 31 is in support at one of its ends on the shoulders 47 of the tie rod 4 and at the other of its ends on the shoulders 57 of the tie rod 5. It is the same for the spring 33.

 Thus thanks to the axial offsets the shoulders 57.58 and 47.48, any interference between the ends of the springs 31, 32, 33 is avoided.

 These springs 31, 32, 33 act between the bases 54, 44 forming a support for said springs.

 It will be noted that the bases 44, 54 are curved by having a curved shape between the teeth to increase the range of the springs 31 to 33 (Figure 3).

 Thanks to the guide tubes 34, 35, 36 and the associated teeth of the tie rods 4.5, the deformation of the springs 31, 32 is avoided under the action of centrifugal force, as well as jamming.

 Here the tie rod 5 is articulated by its central tooth 53 and its hole 56 on a hinge pin 6 carried by the internal periphery of the second mass 2.

 The hinge pin 6 has a shoulder end for holding the free end 53 between said head and the face of the plate 2 facing the plate 11.

 The barrel of the tie rod 6 is clamped in a needle bearing 61 mounted in a hole, which has the plate 2 for this purpose. This hole is mounted between two consecutive through holes 27 (Figure 2). I1 has a size smaller than that of said hole 27.

 In practice, the axis 6 is forcibly engaged in the through hole 56 of the tooth 53, so that the tie rod 5 is mounted at articulation on the mass 2. The tie rod 4 is articulated on an axis 7 whose ends are mounted at articulation, by means of bearings 71 mounted respectively in passages of the plate 11 and in passages of the closing pieces 15 carried by the plate 11 at the external periphery thereof.

 These parts 15 are adjacent to the plate and are attached by screwing onto the plate 11.

 Thus the plate 11 has at its external periphery cavities delimited by the plate 11 and the parts 15 for mounting of the crews 4,5,31 to 36.

 It will be noted that the axis 7 is immobilized axially by means of a circlip 72 wedged axially by the plate 11 and the guide tube 34.

 It will be noted that the rounded shape of the base 44 of the tie rod 4 allows the latter to match the shape of the internal edge of the window 16 and that the shape of the base 54 of the tie rod 5 allows, thanks to the central recess 55 from this, the passage of the axis 7 which increases the length of the springs 31 to 33.

 Thus for the rest position of the damping flywheel the springs 31 to 33 extend parallel to each other, the central spring 32 having a radial orientation for the rest position of the damping flywheel.

 This rest position, here purely radial, is stable. In fact, referring for example to FIG. 6, it can be seen that as soon as the mass 2, for example moves relative to the mass 1, the springs 31, 32, 33 tend to exert a return action towards the position rest. These springs work here in compression.

 Thanks to the arrangement according to the invention, an elastic damping device 3 of variable stiffness is obtained. In fact, thanks to the articulated assembly, the forces exerted by the device 3 decompose into an active tangential force and an inactive radial force directed towards the axis of the assembly (FIG. 6) and collected here by the second mass.

 Thus, for the engine idling speed, the stiffness of the device 3 is low, then it increases continuously for the higher engine speeds (torques), the angular movement between the two masses 1 and 2 increasing.

 Thanks to the invention, large angular deflections can be obtained between the two masses (FIG. 7) comparable to those obtained with the best circumferential action spring devices.

 Thus when starting and stopping the engine of the motor vehicle, one passes through the resonant frequency of the engine and one obtains a very good damping because during this phase the angular movement between the two masses increases rapidly, as well as the stiffness of the elastic damping device 3 according to the invention.

The examination of the different situations of use of the heat engine makes it possible to highlight the advantages brought by the device object of the invention
- when the engine is idling, gearbox in neutral, the low stiffness associated with the low friction of the device ensures optimal filtration
- when the engine is engaged and whatever the speed and the torque transmitted, the evolving characteristic of the torsional stiffness allows the transmission of the torque while ensuring optimal filtration thanks to a level of stiffness which although variable remains sufficiently low and reduced friction
- in the starting and stopping phases of the heat engine, characterized by a very low level of transmitted torque, the very low stiffness characteristic which is continuously variable with the clearance naturally allows the resonance phenomenon to be very greatly attenuated (the resonant frequency becomes variable with the travel) in the absence of any additional friction or locking device.

 There is therefore obtained a damping flywheel with large deflections without having to resort to lubrication of the elastic members of the elastic damping device 3. Thus, in FIG. 7, the angular deflection D in degrees is shown between the two masses and in respectively coordinate the transmitted torque C in Nm and the stiffness in Nm per degree of the elastic device according to the invention. Thus the curve C1 represents the characteristic curve of the transmitted torque and the curve C2 the torsional stiffness curve of the elastic device. It will be noted that the stiffness may be zero in the vicinity of the stable position of rest.

 It will be noted that the friction at the level of the springs 31, 32, 33 is minimized due to the presence of the guides 34 to 36 and that these springs 31, 32, 33 are slightly deformed due to the presence of these ribbed guides 34 to 36 .

 In addition the tie rods 4,5 can easily slide one in contact with the other due to the guides 34 to 36 and the coating 8 with a low coefficient of friction.

 Of course we can reverse the structures.

Thus (FIG. 8) the second mass 2 can be mounted in a journalling manner with respect to the first mass 1 by means of a ball bearing 114 interposed between the external periphery of the masses 2.1.

 To do this, this bearing comprises a piece 115 of sheet metal fixed for example by screwing on the plate 11. This piece 115 forms the outer bearing ring, the inner ring being formed by the outer periphery of the mass 2. In this case, the elastic damping device 3 is mounted with articulation at its outer periphery on the mass 2 and with articulation at its internal periphery on the mass 1, unlike the embodiment of FIG. 1 where said device is mounted with articulation its internal periphery on mass 2 and on its external periphery on mass 1.

 In this exemplary embodiment, the articulation axes 60 and 70 are surrounded by articulation sleeves 161, 171 in which are engaged, through their through hole, the central teeth of the tie rods 4.5. Of course, needle bearings can be provided instead of the sleeves 161, 175.

 In FIG. 9 the articulation axis 600, on which the tie rod 5 is mounted, can be hollow and be mounted by means of a passage hole 127 of the mass 2 for the passage of a tool used for screwing the fixing screw 101. The tool passes through the axis 600 force fitted into the hole 127.

 Of course the presence of the tie rod is not compulsory.

 Thus in FIGS. 10 and 11, the elastic shock absorber device 130 can consist of a metal washer 133 carrying, by means of radial arms, diametrically opposite two sleeves 131, 132 for articulated mounting respectively on axes 6 and 7 of the figure 1.

 In FIG. 12, it can be seen that the elastic damping device 230 can consist of a stack of curved blades 231,232 carrying at each of their ends articulation sleeves 233,234 for articulation mounting of the device 230 on axes 7 and 6 respectively. of figure 1.

 We see in Figure 12, that the elastic damping device has two blades 231 and two blades 232 mounted head to tail while being in contact with each other at their circumferential ends.

 The central blades 231 and 232 are curved and are in contact with each other, the end blades 231 and 232 carrying the articulation sleeves 233 and 234.

 Of course the blades 232, 231 are fixed to each other, for example by welding.

 In Figure 13 the elastic damping device 330 consists of a coil spring with at each of its ends a hooking loop for mounting on the axes 6 and 7 or any other similar device for example bulges from the masses.

 Thus in FIGS. 10 to 13, when one acts on the ends of the elastic damping devices, elastically deforms by traction the central part of these elastic damping devices. The elastic members of the devices of FIGS. 10 to 13 are thus mounted directly by their articulated ends on the first and second masses.

 Of course, while in the preceding figures the elastic members of the elastic damping devices were of the metallic type, as a variant (FIGS. 14 and 15) the elastic damping members 430 may include blocks made of elastic material 431.

 Each block 431 intervenes between two tie rods 432,433 with a generally U-shaped cross section, one of the branches of which is extended to carry an articulation sphere 434,435 for articulation mounting in corresponding semi-spherical cradles practiced in masses 1 and 2 or reported on them.

 Note that block 431 is centrally hollow.

 The block 431 intervenes between the non-extended branches of the tie rods 433,432 mounted head to tail. The block 431 is mounted with adhesion on the branches concerned of said tie rods 432,433, for example by bonding or vulcanization in situ.

 In FIG. 16, the elastic damping devices comprise two supports 633,634 between which a coil spring 631 intervenes radially.

 The support 633 carries a cable fixed with a washer 637 in a recess 636 of one of the masses, here the mass 2. The support 633 can slide along a cable 632. The support 634, in its upper part carries a hinge pin 635 in two parts for hinge mounting on one of the masses.

The cable passes through the lower part of the support. Thus one of the articulations is produced using the cable 632 and the other using the axis 635, the support 633 being able to slide with respect to the support 634 while being guided by said support.

 In FIGS. 17 and 18, the elastic damping device 730 comprises a support 731 of rectangular shape with an upper end 732 in the form of a loop for mounting a centrally hollow articulation axis.

 The side of the support 731 opposite to that carrying the loop 732 is crossed with play by a rod 735 carrying a hollow articulation axis 736. This rod plays with play the block of elastic material 734 and is fixed to a support 733.

 The block 734 is fixed by adhesion to the support 733 and to the concerned side of the support 731.

 We see that the invention opens the way to large numbers of applications and that in Figures 14 to 18 the elastic members worked in compression, so that as a variant there is no need to fix the blocks of material elastic, for example elastomer or rubber. For this, it suffices to mount the blocks under prestressing.

 In a variant, in FIG. 1, the central spring 32 can be omitted, due to the symmetry the two springs 31, 32 intervene purely radially between the two masses for the rest position.

 In FIG. 16, the spring 631 can be replaced by a block of centrally hollow elastic material.

 The same is true in FIGS. 14, 15 and 17, 18, the blocks 431, 731 being able to be replaced by coil springs. In this case you have to support the tie rods to center the springs.

Claims (7)

 1- Shock absorber flywheel, in particular for a motor vehicle, of the type comprising two coaxial masses (1,2) mounted mobile with respect to one another, against an elastic damping device (3,130,230 ...) comprising elastic members (31 to 33 - 133 - 231,232 ...) intervening between the two masses (1,2), in which one of the masses (1,2), called the first mass (1), is intended to be fixed by screws (101) to a driving shaft, such as the crankshaft of the internal combustion engine of a motor vehicle, while the other mass (1,2), called the second mass (2), is pivotally mounted on the first mass (1) using bearing means (14,114) and is intended to be locked in rotation, by means of a friction clutch, on a driven shaft, such as the input shaft of the gearbox of a motor vehicle, said second mass (2) forming the clutch reaction plate, characterized in that the elastic members ticks (31 to 33 133 - 231,232 ...) are hingedly mounted on one and the other of said masses respectively on the outer periphery of the first mass (1) and on the internal periphery of the second mass (2) by means of articulation axes (6,7), and in that each articulation axis (7), carried by the external periphery of the first mass (1), is mounted at its ends on the first mass (1) respectively through a passage made in a tray (11), which has the first mass (1), and through a passage made in a closure part (15) carried by said tray (11) at the outer periphery thereof, so that said elastic members occupy inclined working positions during the relative angular deflections between the two masses (1,2).  2- damping flywheel according to claim 1, characterized in that the closing part (15) is attached by screwing on said plate (11).  3- damping flywheel according to claim 1 or 2, characterized in that the first mass (1) has at its outer periphery cavities each delimited by the plate (11) and the closure part (15).  4- damping flywheel according to claim 3, characterized in that the cavities are used for mounting the crew formed by tie rods mounted head to tail on which are mounted at least one elastic member (31 to 33), said tie rods being mounted at articulation respectively at the internal periphery of the second mass (2) and at the external periphery of the first mass (1) via said hinge pins (6,7), so that said elastic members work in compression.  5- damping flywheel according to claim 4, characterized in that said plate (11) has windows (16) for mounting said elastic members.  6- damping flywheel according to claim 5, characterized in that the windows (16) extend to the vicinity of recesses (17), that has the plate (11) at its outer periphery for mounting said crews.  7- damping flywheel according to claim 6, characterized in that the windows (16) extend from the internal periphery of the plate (11) to said recesses, radially beyond the fixing screws (101), which has the damping flywheel for fixing the first mass (1) to a driving shaft, such as the crankshaft of the internal combustion engine of a motor vehicle.