GB2175370A

GB2175370A - Torsional oscillation damper

Info

Publication number: GB2175370A
Application number: GB08611976A
Authority: GB
Inventors: Paul Maucher
Original assignee: LuK Lamellen und Kupplungsbau GmbH
Current assignee: LuK Lamellen und Kupplungsbau GmbH
Priority date: 1985-05-18
Filing date: 1986-05-16
Publication date: 1986-11-26
Also published as: GB2175370B; FR2582068B1; ATA130186A; DE8605603U1; FR2582068A1; FR2650046A1; AT394095B; GB8611976D0; DE8514735U1

Abstract

A torsional oscillation damper has a pre-damper (2) and a main damper (3) in both of which force storage members (20, 13) are operative between the respective input and output members (5, 8) of said dampers and the output member of the torsional oscillation damper is a hub member (11) which is provided with an internal profile (12) for fitting onto a transmission shaft and which non-rotatably carries the output member (19) of the pre-damper, and also the output member (8) of the main damper by way of an internal profile which is engaged with peripheral play with an external profile of the hub member. In order to give a particularly simple and economical construction as well as to simplify assembly and to improve operation, the pre-damper (2) is such that it only has an input member and an output member of which at least one is a plastics member (18). <IMAGE>

Description

SPECIFICATION Torsional oscillation damper The invention relates to a torsional oscillation damper, in particular for motor vehicle clutch plates comprising a pre-damper having force storage members with a lower degree of stiffness and a main damper having force storage members with a higher degree of stiffness, wherein the force storage members are operative between the respective input and output members of the pre-damper and the main damper and the output member of the torsional oscillation damper is a hub member which is provided with an internal profile for fitting onto a transmission shaft and which non-rotatably carries the output member of the pre-damper and further the output member of the main damper by way of an internal profile which is engaged with an external profile of the hub member and said profiles permit the output member of the main damper a limited relative rotary movement with respect to the output member of the torsional oscillation damper.

In clutch plates as are disclosed for example in GB-A-20 80 488, the pre-damper must be pre-mounted on the outward side of one of the side plates forming the input member of the clutch plate. The construction of the predamper requires for that purpose a multiplicity of individual components, in particular guide plates which are disposed in opposite relationship in pairs and between which a flange extends, while additional rivet pins are necessary for fixing the guide plates to the corresponding side plate.

A clutch plate construction of that kind is comparatively complicated and costly and in addition requires a relatively large amount of space in an axial direction.

The present invention was based on the problem of providing a torsional oscillation damper of the kind set forth in the opening part of this specification, which is of a particularly compact construction and thus requires a comparatively small amount of space, which further ensures satisfactory actuation and guidance in respect of the springs of the predamper, and which is particularly simple in structure. The invention further seeks to ensure ease of assembly as well as economical manufacture and reliable operation of the torsional oscillation damper.

In accordance with the invention, in a torsional oscillation damper of the kind set forth in the opening part of this specification, that is achieved in that the pre-damper has an input member and an output member which each comprise a disc-like component and of which at least one is a plastics member which has receiving pockets disposed in the peripheral direction for receiving the at least approximately tangentially disposed force storage members of the pre-damper and the receiving pockets at least partially enclose the force storage members and have regions co-operating with the ends of the force storage members.Such a construction for the torsional oscillation damper is particularly simple and economical as, apart from the force storage members, the pre-damper may have only two parts, namely the input member and the output member, while-furthermore the use of a plastics member with receiving pockets for the force storage members ensures satisfactory mounting and guidance for the force storage members. In addition plastics members can be produced in a particularly simple and rational manner, for example by the injection moulding of fibre-reinforced plastics materials. A further advantage of such plastics members is that there is a wide range of possible variations in regard to the configuration thereof, whereby they can be adapted to the existing space requirements in a particularly simple fashion.

It may be advantageous for the receiving pockets to be of such a configuration that the plastics member embraces the force storage members over a substantial part of their periphery. In that respect it may be desirable for the receiving pockets to be such that the force storage members are embraced by the plastics member over at least 1800 of the periphery. Such a configuration for the receiving pockets permits the force storage members of the pre-damper to be satisfactorily mounted and held in position. It may be desirable in that arrangement if at least approximately the radially outward half of the respective force storage members is surrounded by the plastics member, thereby ensuring that the force storage members are satisfactorily secured in position in a radial direction.

Furthermore, the configuration of the torsional oscillation damper according to the invention can ensure that the ends of the force storage members of the pre-damper are satisfactirly acted upon as the regions of the plastics member which co-operate with said ends may be such that they can act on the force storage members at least at two diametrally oppositely disposed points.

It may be advantageous for at least the output member of the pre-damper or at least the input member of the pre-damper to be formed by a plastics member. For many situations of use however it may also be desirable for both the output member and the input member to comprise plastics material.

It may be particularly desirable for the plastics member to form a disc-like component having two axially oppositely directed sides and for the receiving pockets to extend from one of the sides axially into said component.

It may be advantageous in that respect for the receiving pockets to be closed in the axial direction towards the other of the sides. It may also be advantageous if, as considered in the peripheral direction, the receiving pockets communicate with slots which extend in a circularly arcuate configuration. In that respect the slots may extend axially into the plastics member from the same side as the receiving pockets. A plastics member of that kind, provided with slots, is particularly advantageously suitable for a pre-damper which has a second component having axially directed projections which can engage into the slots and co-operate with the end regions of the force storage members of the pre-damper.It may be particularly advantageous in that connection for the axial projections to extend over a dimeter of the force storage members of the pre-damper, while it may further be desirable for the second component which has the axial projections to form the output member of the predamper. For many situations of use however it may also be advantageous for the second component to form the input member of the pre-damper.

It may be particularly advantageous for -the receiving pockets, starting from their open side, to have regions which extend inclinedly outwardly and with their radially outward portion respectively to form a radial undercut configuration in the plastics member, thereby ensuring that the force storage members which are contained in the receiving pockets are also satisfactorily held in position in the radial direction.

It may be particularly advantageous for the torsional oscillation damper to be of such a construction that the plastics member additionally serves as a friction ring.

The torsional oscillation damper can be of a particularly advantageous construction if the second component is a sheet metal member which has a radial annular region, at the radially outward periphery of which are provided arms which are bent over axially and which engage into the slots in the plastics member, and at the radially inward periphery of which are provided radially directed teeth which cooperate with the external profile of the hub member which forms the output member of the torsional oscillation damper.

In relation to torsional oscillation dampers with an input member which is formed by two spaced-apart side discs or plates which accommodate between them a flange forming the output member of the main damper, it may be particularly advantageous for the predamper to be arranged axially between the flange and one of the side plates forming the input member of the torsional oscillation damper. With the torsional oscillation damper being of such a design, the axial space which is to be found anyway in most cases between the side plates forming the input member of the torsional oscillation damper and the hub member forming the output member of the main damper can be advantageously used for the pre-damper.In addition, by virtue of the axial displacement as between the force storage members of the main damper and the force storage members of the pre-damper, the force storage members of both dampers can be moved closer to each other in the radial direction, thereby providing that the damper is of a compact construction. With such a design configuration for the torsional oscillation damper, the plastics member can advantageously be gripped axially between the flange of the main damper and one of the side plates, whereby it can additionally produce a frictional damping action in the event of relative rotary movement as between the input member and the output member of the main damper.Furthermore, in such a construction in respect of the torsional oscillation damper, it may be advantageous for the output member of the predamper to be disposed axially between the plastics member and the flange of the main damper, while in that respect it may be desirable for the output member of the pre-damper to have an axial clearance between the plastics member and the flange of the main damper. The latter feature avoids undesirable friction.

It may also be advantageous .for the plastics member which forms the input member of the pre-damper to engage axially over the output member of the pre-damper and to be nonrotatable with respect to the flange of the main damper. In that arrangement the input member of plastics material may bear against the flange over the entire periphery, whereby the pre-damper is encapsulated in a radially outward direction.

In order to secure the plastics member nonrotatably with respect to the flange forming the output member of the main damper, it may be desirable for the plastics member to be provided at its side which is towards the flange with axial projections such as lugs which engage into openings or cut-outs in the flange.

Furthermore, in relation to torsional oscillation dampers in which the knput member is formed by two axially spaced-apart side plates which accommodate between them a flange forming the output member of the main damper, wherein the pre-damper is arranged between said flange and one of the side plates, it may be advantageous if arranged on the side of the flange, which is remote from the plastics member, is a force storage member such as a diaphragm spring which is prestressed between said side and the other side plate of the input member of the torsional oscillation damper, which diaphragm spring ensures that the plastics member is axially braced between the flange of the main damper and the one side plate.

In accordance with a further feature of the invention, the plastics member may have mounting slope means for insertion of the force storage members of the pre-damper, which means start from the open side of the receiving pockets and terminate at the end regions of the receiving pockets, which co-operate with the ends of the force storage members. Such mounting slope means make it easier to assemble the torsional oscillation damper.

For many situations of use it may also be particularly advantageous for the disc-like components forming the input and output members of the pre-damper to be arranged radially one above the other. Designing the pre-damper in that way requires a particularly small amount of space in the axial direction. It may be advantageous in that respect for the output member of the pre-damper to be accommodated within the input member. In that arrangement it may be particularly desirable for the input member and the output member of the pre-damper to be arranged at least approximately at the same axial level.In addition, in such a design configuration of the predam per, it may be particularly advantageous for both the input member and also the output member of the pre-damper to comprise plastics members which have half shell-like receiving pockets which are disposed in mutually opposite relationship and which receive and embrace the force storage members of the pre-damper.

For actuation of the pre-damper of a torsional oscillation damper according to the invention, it may further be advantageous, in regard to many situations of use, for the input member of the pre-damper to have arms/openings or the like which co-operate with springs with a higher degree of stiffness of the main damper, in such a way that the input member of the pre-damper is driven or entrained by said higher-stiffness springs at least over a part of the possible overall angle of rotary motion as between the input member and the output member of the torsional oscillation damper.

The invention will now be described in greater detail with reference to Figs. 1 to 6 in which: Figure 1 is a sectional view of a clutch plate, Figure 2 shows the upper side of the sectional view of Fig. 1, on an enlarged scale, Figure 3 shows the lower side of the sectional view of Fig. 1 on an enlarged scale, Figure 4 shows the plastics member forming the input member of the pre-damper of the clutch plate shown in Figs. 1 to 3, Figure 5 is a view in section taken along line V-V in Fig. 4, and Figure 6 shows a further embodiment of a clutch plate constructed in accordance with the invention.

The clutch plate 1 shown in the drawings comprises a pre-damper 2 and a main damper 3. The input member of the clutch plate 1 which at the same time represents the input member of the main damper 3 is formed by a drive disc 5 carrying friction linings or facings 4, and a counter-disc 7 which is non-rotatably connected thereto by way of spacer pins 6.

The output member of the main damper 3 is formed by a flange 8 which has internal splines 9 which engage into external splines 10 on a hub member 11 forming the output member of the clutch plate 1. Provided between the side faces of the external splines 10 on the hub member 11 and the side faces of the internal splines 9 of the flange 8, in the peripheral direction, is a clearance which corresponds to the operative range of the predamper 2. The hub member 11 further has internal splines 12 for mounting on a transmission input shaft.

The main damper 3 has springs 13 which are provided in window-like openings 14 and 15 in the discs 5 and 7 on the one hand and in window-like openings or cut-outs 16 in the flange 8 on the other hand. Relative rotary movement against the force of the springs 13 is possible, as between the disc 5 and 7 which are non-rotatably connected together, and the flange 8. Such rotary movement is limited by the spacer pins 6 which interconnect the two discs 5 and 7 butting against the end contours of the openings 17 in the flange 8 through which they axially project.

The pre-damper 2 is arranged axially between the flange 8 and the drive disc 5. The input member of the pre-damper 2 is formed by a plastis member 18 which is advantageously fibre-reinforced. The plastics member 18 is non-rotatably connected to the flange 8.

The output member 19 of pre-damper 2 is formed by a sheet metal member which is non-rotatably connected to the hub member 11. Limited relative rotary movement corresponding to the clearance between the side faces of the external splines 10 on the hub member 1 and the internal splines 9 on the flange 8 is possible as between the plastics member 18 and the sheet metal member 19, more specifically against the force of force storage members in the form of compression coil springs 20, which are operative therebetween.

The plastics member 18 is of an annular disc-like configuration with two axially oppositely directed side surfaces 21 and 22. Provided on the side of the flange 8 which is remote from the plastics member 18 is a diaphragm spring 23 which is axially gripped between the disc 7 and the flange 8. The prestressed diaphragm spring 23 provides that the flange 8 is loaded in the direction of the facing-carrier disc 5, whereby the plastics member 18 is axially gripped between the disc 5 and the flange 8 on the hub.

Radially inwardly, the diaphragm spring 23 has a rounded-off portion 24 by way of which it bears against the flange 8. Provided at the outer periphery of the diaphragm spring 23 are individual arms 25 which engage into openings 26 in the disc 7 in order to prevent the diaphragm spring 23 from rotating relative to the disc 7.

The plastics member 18 is non-rotatably connected to the flange 8 forming the output member of the main damper 3, by way of positive push-in connections. For that purpose the plastics member 18 is provided with axial plug-like or peg-like projections 27 on its side 22 which is towards the flange 8. The projections 27 extend into openings 28 in the flange 8. The projections 27 serve at the same time for centering the plastics member relative to the flange 8.

The plastics member 18 which forms the input member of the pre-damper 2 has receiving pockets 29 in which the springs 20 of the pre-damper are received. As can be seen from Fig. 4, the illustrated embodiment has two pairs of receiving pockets which, as considered in the tangential or peripheral direction, are of different lengths, whereby a two-stage spring characteristic curve can be produced in the angular range of rotary movement of the pre-damper. The receiving pockets 29 of each pair are disposed in diametrally opposite relationship.

The receiving pockets 29 which extend in the peripheral or tangential directions embrace or enclose or surround the springs 20 in the peripheral direction over an angle which is greater than 1800 in the illustrated embodiment. Starting from their side which is towards the flange 8, the receiving pockets 29 extend axially into the plastics member 18. In that connection the depth of the receiving pockets 29 is such that the springs 20 are at least approximately completely accommodated in the plastics member 18. Furthermore the bottom of the receiving pockets 29 is closed, that is to say there is no opening or aperture between the receiving pockets 29 and the side 21 of the plastics member 18, which bears against the facing-carrier disc 5.The ends of the receiving pockets, as considered in the peripheral direction, form contact regions 30 and 31 against which the ends of the springs 20 can bear. As can be seen in particular from Fig. 4, the contact regions 30 and 31 form a comparatively large contact area for the ends of the springs 20. That arrangement ensures that the springs 20 can be acted upon over their total width, that is to say therefore over their diameter, so that the end turns of the springs 20 are not loaded at one side.

As can be seen in particular from Figs. 3 and 5, the receiving pockets are of such a configuration that, starting from the side 22 of the plastics member 18, they also extend radially outwardly, as considered over their axial extent, whereby radial undercut configurations 32 are formed in the plastics member 18, those configurations 32 ensuring that the springs 20 are better mounted or axially secured in the plastics member 18. For that purpose the receiving pockets 29 have inclinedly extending regions 33 and 34 which start from the open side of the receiving pockets.

The plastics member 18 further has slots 35 which extend in a circularly arcuate configuration in the peripheral direction and which communicate with the receiving pockets 29.

The slots 35 extend axially into the plastics member 18 from the same side 22 as the receiving pockets 29. In that connection the depth of the slots 35 is such that they extend transversely with respect to the axis of the force storage members 20 and are deeper than the diameter of the force storage members 20.

The sheet metal member 19 which forms the output member of the pre-damper 2 and which is arranged axially between the plastics member 18 and the flange 8 has a radially extending annular region 19a which is disposed around the hub member 11. Provided at the radially outward periphery of the annular region 19a are arms 36 which are bent over axially and which are integral with the sheet metal member 19. The axial arms 36 extend into the slots 35 in the plastics member 18 and are distributed over the periphery thereof in such a way that they can co-operate with the ends of the force storage means 20 at least in the event of relative rotary movement as between the plastics member 18 and the sheet metal member 19, whereby the force storage members 20 are compressed.In order to ensure that the force storage members 20 are satisfactorily acted upon, the axial arms 36 extend over the entire diameter of the force storage members 20. Formed at the radially inward periphery of the annular region 19a of the sheet metal member 19 are radially inwardly directed teeth 1 9b which engage into the external splines 10 on the hub member 11. That engagement prevents the sheet metal member 19 from rotating relative to the hub member 11, although the sheet metal member 19 still enjoys the possibility of axial displacement with respect to the hub member 11. In order to ensure that excessive friction does not occur in the event of relative rotary movement of the flange 8 and also the plastics member 18 which is non-rotatable with respect thereto, relative to the output member 19 of the pre-damper 2, which is non-rotatable with respect to the hub member 11, the plastics member 18 is of such a configuration that the annular region 19a has at least a small axial clearance 37, between the plastics member 18 and the flange 8. The plastics member 18 is further of such a configuration that it engages radially outwardly completely over the sheet metal member or output member 19, so that the pre-damper 2 is encapsulated in an outward direction.

For greater ease of assembly of the pre damper 2, the plastics member has mounting slope means 370 & 380 for insertion of the force storage members 20. The slope means 37 and 38 start from the open side of the receiving pockets 29 and extend inclinedly to the contact regions 30, 31 which co-operate with the ends of the force storage members 20. The slope means 37 and 38 are thus arranged to define a funnel-like configuration so that they form a guide means for the force storage members 20, thereby facilitating the operation of mounting the force storage members 20 into the receiving pockets 29.

The axial projections 27 which ensure that the plastics member 18 is centered and secured non-rotatably with respect to the flange 8 are provided at their free ends with respective tapering portions 27a which facilitate insertion into the openings 28 and thus make it easier to assemble the clutch plate.

The drive disc 5 is mounted on a shoulder 40 of the hub member 11 by way of a Lshaped friction or sliding ring 38.

Arranged between the radially extending limb of the ring 38, which carries the drive disc 5, and the step 42 adjoining the shoulder 40 is a prestressed corrugated disc 43 which urges the drive disc 5 axially away from the external splines 10, whereby the radial friction or slide ring 39 is axially gripped between the counterdisc 7 and the end face 41 of the external splines 10. The ring 39 has internal splines 39a which engage into a spline region 10a which is set back radially with respect to the splines 10.

Starting from the neutral position of the clutch plate 1, in the event of a relative rotary movement between the discs 5 and 7 forming the input member of the clutch plate 1, relative to the hub member 11, the force storage members 20 of the pre-damper 2 and the two friction or slide rings 38 and 39 work first.

As soon as the clearance between the side faces of the external splines 10 of the hub member 11 and the internal splines 9 of the flange 8 has been taken up, the pre-damper 2 is by-passed so that, in the event of a continuation of a relative rotary movement between the two discs 5, 7 and the hub member 11, only the force storage members 13 of the main damper 3 are operative. In addition to the force storage members 13, a frictional damping effect is operative over the range of rotary movement of the main damper 3, the frictional damping effect being produced both by the two frictional or slide rings 38, 39 and also and predominantly by virtue of friction of the diaphragm spring 23 against the flange 8 and by friction of the plastics member 18 against the facing-carrier disc 5.For the purposes of actuation of the pre-damper 2, the plastics member 18 may have radially outwardly extending arms or projection portions 44, instead of the axial projections 27 which non-rotatably connect the plastics member 18 to the flange 8; the arms 44 are shown in dash-dotted lines in Fig. 2 and engage the ends of the springsl3 of the main damper 3, which have a substantially higher level of spring stiffness than the springs 20 of the pre-damper 2.

In the embodiment shown in Figs. 1 to 3, the output member 19 of the pre-damper 2 is formed by a shaped sheet metal member.

However the output member 19 may also be in the form of a plastics member, in which case it must then be of suitable dimensions according to the strength of the plastics material used.

It is also advantageous if, as in the case of the embodiment shown in Figs. 1 to 3, the pre-damper 2 is arranged radially within the springs 13 of the main damper 3.

In the embodiment illustrated in Fig. 6, the pre-damper 102, as considered in the axial direction, is disposed outside of the axial space defined by the spacing-carrier disc 105 and the counter-disc 107. The flange 108 has at a radially inward position a hub region 108a having internal splines 109 with which it engages, with peripheral play, into the external splines 110 on the hub flange 111. The discs 105 and 107 are guided in the radial direction on the hub region 108a.

The pre-damper 102 has an input member 118 and an output member 119 which are made of plastics material. The output member 119 has internal splines 1 19b which engage into the external splines 110 of the hub member 11 in order non-rotatably to secure the output member 119 relative to the hub member 111. Radially inwardly, the output member 119 has an axial projection 145 which engages axially into a suitably matched recess 146 in the hub region 108a. The recess 146 and the projection 147 are matched to each other in such a way that the flange 108 or the hub region 108a is mounted in the radial direction on the axial projection 145 by way of the outside peripheral surface of the recess 146.Provided at the outer end of the hub region 108a is an angular bush 147 which also has radially inward splines 147a engaging with the external splines 110 on the hub member 111. The axial region 147b of the bush 147 extends into a recess 146a in the hub region 108a. The recess 146a and the axial region 147b are matched to each other in such a way that the hub region 108a is mounted on the axial region 147b by way of the inward peripheral surface of the recess 146a, whereby the flange 108 is guided in the radial direction with respect to the hub member 111.

In order to accommodate the springs 120 of the pre-damper 102, the output member 119 is provided at its outward peripheral region with receiving pockets 129. In a similar fashion, the input member 118 has receiving pockets 148 at its radially inward peripheral region. The receiving pockets 129 and 148 are provided in the output member 119 and the input member 118 in such a way that the springs 120 are enclosed or surrounded by the input member 118 and the output member 119 so that the springs cannot fall out of the pockets 129 and 148. For that purpose, the input member 118 is provided at its inward periphery and the output member 119 at its outward periphery with step portions which are complementary to each other and which permit the output and input members 119 and 118 to be both radially and axially secured relative to each other.

For the purposes of actuation of the predamper 102, the input member 118 has radially outwardly directed arms 144 which cooperate with the ends of springs 113 of the main damper, which have a higher level of stiffness than the springs 120 of the pre-damper 102.

Securing rings 149 and 150 are provided on the hub member 111 on both sides of the hub region 108a, for axially securing the flange 108 on the hub member 111. Arranged between the securing ring 150 and the mounting or slide ring 147 is a corrugated spring 151 which urges the ring 147 towards the second securing ring 149 whereby the components disposed between the two securing rings 149 and 150, namely the slide ring 147, the hub region 1 08a and the output member 119, are axially braced together.

The invention is not restricted to the illustrated embodiments but related quite generally to clutch plates, in particular also to those clutch plates in which the output member of the main damper has two axially spaced-apart side plates between which is accommodated the facing-carrier plate forming the input member. In that arrangement the side plates may be non-rotatably carried on a hub portion having internal splines which engage with play into the external splines of an inner hub portion which further has internal splines for mounting for example on a transmission shaft.

Claims

1. A torsional oscillation damper, in particular for motor vehicle clutch plates comprising a pre-damper having force storage members with a lower degree of stiffness and a main damper having force storage members with a higher degree of stiffness, wherein the force storage members are operative between the respective input and output members of the pre-damper and the main damper and the output member of the torsional oscillation damper is a hub member which is provided with an internal profile for fitting onto a transmission shaft and which non-rotatably carried the output member of the pre-damper and further the output member of the main damper by way of an internal profile which is engaged with an external profile of the hub member and said profiles permit the output member of the main damper a limited relative rotary movement with respect to the output member of the torsional oscillation damper characterised in that the pre-damper (2, 102) has an input member and an output member (18, 19, 118, 119) which each comprise a disc-like component (18, 118, 119) and of which at least one is a plastics member (18, 118, 119) which has receiving pockets (29, 129, 148) disposed in the peripheral direction for receiving the at least approximately tangentially disposed force storage members (20, 120) of the pre-damper (2, 102) and the receiving pockets at least partially enclose the force storage members (20, 120) and have regions (30, 31) co-operating with the ends of the force storage members (20, 120).

2. A torsional oscillation damper according to claim 1 characterised in that the receiving pockets (29, 129, 148) enclose the force storage members (20, 120) over at least approximately 1800.

3. A torsional oscillation damper according to claim 1 or claim 2 characterised in that the plastics member (18) acts on the force storage members (20) at least at two diagonally oppositely disposed points.

4. A torsional oscillation damper according to one of claims 1 to 3 characterised in that the plastics member (119) forms the output member of the pre-damper (102).

5. A torsional oscillation damper according to one of claims 1 to 3 characterised in that the plastics member (18, 118) forms the input member of the pre-damper (2, 102).

6. A torsional oscillation damper according to one of claims 1 to 5 characterised in that the plastics member (18) forms a disc-like component with two axially oppositely directed sides (21, 22) and the receiving pockets (29) extend from one (22) of the sides (21, 22) axially into same.

7. A torsional oscillation damper according to claim 6 characterised in that the receiving pockets (29) are closed in the axial direction towards the other of the sides (21).

8. A torsional oscillation damper according to one of claims 1 to 7 characterised in that, as considered in the peripheral direction, the receiving pockets (29) communicate with slots (35) which extend in a circularly arcuate configuration.

9. A torsional oscillation damper according to claim 8 characterised in that the slots (35) extend axially into the plastics member (18) from the same side (22) as the receiving pockets (29).

10. A torsional oscillation damper according to at least one of the preceding claims characterised in that the pre-damper (2) has a second component (19) having axially directed projections (36) which engage into the slots (35) of the plastics member (18) and co-operate with the end regions of the force storage members (20) of the pre-damper.

11. A torsional oscillation damper according to claim 10 characterised in that the axial projections (36) extend over a diameter of the force storage members (20) of the pre-damper (2).

12 A torsional oscillation damper according to claim 10 of claim 11 characterised in that the second component (19) forms the output member of the pre-damper (2).

13. A torsional oscillation damper according to claim 10 or claim 11 characterised in that the second component forms the input member of the pre-damper.

14. A torsional oscillation damper according to one of the preceding claims characterised in that the receiving pockets (29), starting from the open side thereof, have regions (33, 34) which extend inclinedly outwardly and with their radially outward portion each form a respective undercut configuration (32) in the plastics member (18).

15. A torsional oscillation damper according to one of claims 1 to 12 characterised in that the plastics member (18, 118, 119) additionally serves as a friction ring.

16. A torsional oscillation damper according to one of claims 10 to 15 characterised in that the second component (19) is a shaped sheet metal member which has a radial annular region (19a) at the radially outward periphery of which are provided arms (36) which are bent over axially and which engage into the slots (365) of the plastics member (18), and which at its radially inward periphery has radially directed teeth (19b) which co-operate with the external profile (10) of the hub member (11) forming the output member of the torsional oscillation damper.

17. A torsional oscillation damper according to one of the preceding claims wherein the input member of the torsional oscillation damper is formed by two axially spaced side discs which accommodate between them a flange forming the output member of the main damper, characterised in that the pre-damper (2) is arranged axially between the flange (8) and one (5) of the side discs (5, 7) which form the input member of the torsional oscillation damper.

18. A torsional oscillation damper according to claim 17 characterised in that the plastics member (18) is gripped axially between the flange (8) of the main damper (3) and one (5) of the side discs (5, 7).

19. A torsional oscillation damper according to one of claims 17 and 18 characterised in that the output member (19) of the predamper (2) is arranged axially between the plastics member (18) and the flange (8) of the main damper (3).

20. A torsional oscillation damper according to claim 19 characterised in that the output member (19) of the pre-damper (2) has an axial clearance (37) between the plastics member (18) and the flange (8) of the main damper (3).

21. A torsional oscillation damper according to one of the preceding claims characterised in that the plastics member (18) engages axially over the output member (19) and is non-rotatable with respect to the flange (8) of the main damper (3).

22. A torsional oscillation damper according to one of claims 1 to 21 characterised in that on its side (22) which is towards the flange (8) of the main damper (3) the plastics member (18) has axial projections (27) which engage into openings (28) in the flange (8) of the main damper (3).

23. A torsional oscillation damper according to one of claims 1 to 22 characterised in that disposed on the side, which is remote from the plastics member (18), of the flange (8) of the main damper (3) is a force storage member (23) such as a diaphragm spring which is prestressed between said side and the other side disc (7) of the input member of the torsional oscillation damper (1), which member (23) ensures that the plastics member (18) is axially braced between the flange (8) of the main damper (3) and the one side disc (5).

24. A torsional oscillation damper according to one of claims 1 to 23 characterised in that the plastics member (18) has mounting slope means (37, 38) for insertion of the force storage members (20) of the pre-damper (2), which start from the open side of the receiving pockets (29) and which terminate at the end regions (30, 31) of the receiving pockets (29), which co-operate with the ends of the force storage members (20).

25. A torsional oscillation damper according to at least one of the preceding claims characterised in that the disc-like components forming the input and output members (118, 119) of the pre-damper (102) are arranged radially one above the other.

26. A torsional oscillation damper according to claim 26 characterised in that the output member (119) of the pre-damper (102) is accommodated radially inwardly of the input member (118) of the pre-damper (102).

27. A torsional oscillation damper according to claim 26 or claim 27 characterised in that the input member (118) and the output member (119) of the pre-damper (102) are arranged at least approximately at the same axial level.

28. A torsional oscillation damper according to at least one of the preceding claims characterised in that the both the input member (118) and also the output member (119) of the pre-damper (102) have half shell-like receiving pockets which are disposed in mutual opposition and which accommodate and embrace the force storage members (120) of the pre-damper (102).