GB2157801A - Motor vehicle friction disc clutch - Google Patents

Abstract

The motor vehicle friction disc clutch comprises two fly-wheel discs (101, 111) rotationally elastically coupled with one another through an under-load torsional vibration damper (109), of which a first fly-wheel disc (101) is secured to the crank-shaft (107). The second fly-wheel disc 111 utilised as counter-presser plate of the clutch disc (117) is secured to the external circumference of a disc part (143) of the under-load vibration damper (109). The disc part (143) is mounted by its internal circumference through a bearing (145) on a separate bearing extension (149) of the first fly- wheel disc (101). In this way the bearing (145) is thermally as well as mechanically decoupled from the fly-wheel disc (111) serving as counter-presser plate. The torsional vibration damper (109) is dimensioned exclusively for operation under load. A torsional vibration damper dimensioned exclusively for idling operation is provided in the region of the hub (119) of the clutch disc (117) and couples the clutch disc (117) rotationally elastically with the gear input shaft (123). <IMAGE>

Description

SPECIFICATION Motor vehicle friction disc clutch The invention relates to a motor vehicle friction disc clutch and especially a clutch comprising a fly-wheel consisting of two fly-wheel discs connected with one another through a rotationally elastic vibration damper.

From Fed. German P.S. 2,931,423 a friction disc clutch for a motor vehicle is known which comprises two fly-wheel discs of substantially annular disc form coupled with one another through a rotationally elastic vibration damper. The first fly-wheel disc, secured to the crank-shaft, carries in the region of its internal circumference a bearing extension on which the second fly-wheel disc is borne through a hub part. The second fly-wheel disc forms the thrust plate unit of the clutch. The second fly-wheel disc is screwed in the region of its internal circumference to a hub part of the rotationally elastic vibration damper which is mounted through a plain bearing on the bearing extension of the first fly-wheel disc.A disc part of the vibration damper, guided in the region of its external circumference on the first fly-wheel by means of a friction device, fixes the hub part in the axial direction. Side discs are provided on the hub part axially on both sides of the disc part, The springs of the vibration damper are seated in windows of the disc part and of the side discs and are resiliently stressed in the relative rotation of the two fly-wheels.

In operation the temperature of the second fly-wheel disc, which serves as counter-presser plate of the clutch, can rise to about 350"C.

In the known clutch this high temperature acts by a very short path directly upon the plain bearing. This leads to problems in the lubrication of the plain bearing. Furthermore bearing play can occur by reason of high temperature differences. Moreover the danger exists that the second fly-wheel disc, serving as counter-pressure plate may come as a result of the high temperature and by reason of the doming high bearing forces may occur which can destroy the plain bearing.

From Fed. German P.S. 2,826,274 a further friction disc clutch for a motor vehicle is known the fly-wheel of which likewise consists of two fly-wheel discs coupled with one another through a rotationally elastic vibration damper. In this fly-wheel again the first flywheel disc secured to the crank-shaft carries a bearing extension on which the second flywheel disc is mounted directly by a plain bearing. To this extent the problems explained above arise.

Axially to both sides of the first fly-wheel disc there are arranged side discs which are connected into one unit with one another and with the second fly-wheel disc. Springs of a vibration damper which couples the two flywheel discs rotationally elastically with one another are arranged in windows of the first fly-wheel disc and of the two side discs. The vibration damper is dimensioned for operation under load and comprises a friction damper.

The clutch disc, which is not explained further, is of relatively expensive design, as far as can be seen from the drawing. The clutch disc comprises a hub part with a hub flange and a disc part with two side discs arranged axially on both sides of the hub flange. The design has similarity with a vibration damper such as is also present in other clutch discs.

The clutch disc of the known clutch has a comparatively great inertia moment and thus is a burden to the synchronisation devices of the motor vehicle gears, in gear-changing.

It is the problem of the invention to produce a motor vehicle friction disc clutch having two fly-wheel discs coupled rotationally elastically with one another which works reliably even in the case of great temperature fluctuations within the clutch and furthermore is easy to fit.

In the friction disc clutch according to the invention the vibration damper, preferably dimensioned for operation under load, including its friction damper if provided, is arranged axially between the two fly-wheel discs. It comprises two outer disc parts, which are connected with one another into a unit and are held fast in rotation as a unit on the first fly-wheel disc, which is screwed to the crankshaft, and an inner disc part arranged between the outer disc parts. The disc parts are supported on one another rotationally elastically through springs, similarly to conventional vibration dampers. The inner disc part is mounted in the region of its internal circumference rotatably on a bearing extension of the first fly-wheel disc. The second fly-wheel disc is secured in the region of its external circumference to the external circumference of the inner disc part.In this way a comparatively long heat removal path is obtained between the second fly-wheel disc and its mounting on the bearing extension of the first fly-wheel disc. The second fly-wheel disc is utilised as counter-presser plate of the clutch disc, and may distort without detriment to the bearing mounting. The second fly-wheel disc is expediently secured with screws to the inner disc part and in this way can be mounted without problem, together with the other components of the clutch.

The clutch cover is expediently secured to the inner disc part at the same time, with the same screws.

The inner disc part of the vibration damper is preferably mounted on an annular bearing extension which is separate from and removably connected with the first fly-wheel disc.

Such a bearing extension simplifies the production and fitting of the bearing and especially permits the use of ball bearings in place of plain bearings. The bearing extension is preferably centred on the first fly-wheel disc through centring elements, for example an annular shoulder of the first fly-wheel disc through centring elements, for example an annular shoulder of the first fly-wheel disc.

The screws provided for the securing of the first fly-wheel disc on the crank-shaft are expediently also used for the securing of the bearing extension.

The outer disc part of the vibration damper, combined into one unit, can be secured for example by riveting of the outer disc part, adjacent to the first fly-wheel disc, to the first fly-wheel disc. The assembly of the clutch on the other hand can be considerably simplified if one of the outer disc parts, preferably the disc part adjacent to the first fly-wheel disc, comprises on its internal circumference a toothing which engages fast in rotation in a matching toothing of the bearing extension which is detachably secured to the first flywheel disc. In this way the vibration damper, including the second fly-wheel disc and the other components of the clutch, can be fitted subsequently to the first fly-wheel disc and the crank-shaft by means of screw connections.

A further aspect of the invention, which can also be utilised in other motor vehicle friction disc clutches having two fly-wheel discs rotationally elastically coupled with one another, concerns the configuration of the vibration dampers. The vibration damper which couples the two fly-wheel discs rotationally elastically with one another includes a friction damper and is dimensioned exclusively for operation under load. The clutch disc likewise comprises a vibration damper which however is dimensioned exclusively for idling operation. In this way the object is achieved that both vibration dampers can be dimensioned optimally for the working ranges. Since the vibration damper of the clutch disc is dimensioned solely for idling operation, the weight of the clutch disc and thus its inertia moment can be kept very small.The clutch disc comprises a hub and a disc part of annular disc form carrying the clutch friction linings and mounted on the hub part for rotation through a limited angle of rotation in relation thereto. The idling vibration damper is arranged in the region of the hub part, that is to say relatively close to the axis of rotation of the clutch disc. The idling vibration damper has a spring rating of the order of magnitude of 0.1 to 0.3 Nm/degree, for which very small springs can be used.

Due to the limitation of the angle of rotation of the disc part in relation to the hub part the idling vibration damper is bridged over on transition into operation under load. In a preferred form of embodiment the limitation of angle of rotation is achieved in that the hub part has on its external circumference an external toothing in which an internal toothing of a foot part firmly connected with the disc part engages with play in the circumferential direction. The idling vibration damper is secured for the one part of the hub part and the for the other on the foot part, for the rotationally elastic coupling of the disc part with the hub part. For this purpose the hub part protrudes axially beyond the foot part.

A suitable form of embodiment of the idling vibration damper comprises a hub disc protruding radially from the hub part and two side discs held on the foot part and arranged axially on both sides of the hub disc. The side discs are supported rotationally elastically on the hub disc through the springs of the idling vibration damper. In order to keep the weight and inertia moment of the clutch disc low, the external diameter of the hub disc and of the side discs is preferably smaller than the internal diameter of the inner disc part of the under-load vibration damper.

Examples of embodiment of the invention are to be explained in greater detail below by reference to drawings, wherein:- Figure 1 shows an axial longitudinal section through the upper half of a first form of embodiment of a motor vehicle friction disc clutch having two fly-wheel discs coupled rotationally elastically with one another; Figure 2 shows a partial sectional view of one of the two fly-wheel discs seen at a point offset in angle in comparison with Fig. 1, and Figure 3 shows an axial longitudinal section through the upper half of another form of embodiment of a motor vehicle friction disc clutch having two fly-wheel discs coupled rotationally elastically with one another.

The motor vehicle friction disc clutch as illustrated in Fig. 1 comprises a first fly-wheel disc 1 of substantially annular disc form, which is secured in the region of its internal circumference with screws 3 to a crank-shaft 7, rotating about an axis 5 of rotation, of the internal combustion engine (not shown further) of the motor vehicle. A second fly-wheel disc 11 is coupled rotationally elastically with the first fly-wheel disc 1 through a torsional vibration damper 9 dimensioned for operation under load. On the one side axially remote from the first fly-wheel disc 1 a presser plate 1 3 is arranged which is guided in the usual way fast in rotation but axially displaceably on the second fly-wheel disc 11, utilised as counter-presser plate, for example by means of tangential straps or the like (not shown further). Friction linings 1 5 of a clutch disc 17, the hub part 1 9 of which is coupled fast in rotation but axially displaceably through a toothing 21 with a gear input shaft 23 of a motor vehicle transmission (not represented further), can be clamped in axially between the presser plate 1 3 and the second fly-wheel disc 11. A clutch cover 25, which grasps over the clutch disc 1 7 and the presser plate 1 3 and on which a diaphragm spring 29 is supported through support rivets 27, is further connected with the second fly-wheel disc 11.The diaphragm spring 29 bears with its external circumference upon noses 31 of the presser plate 1 3 and presses the presser plate 1 3 through the friction linings 1 5 against the second fly-wheel disc 11. To release the clutch tongues 33 of the diaphragm spring 29 are moved by means of a release system (not shown) in the direction towards the second fly-wheel disc 11, whereby the presser plate 1 3 is relieved and lifted away from the clutch disc 17.

The torsional vibration damper 9 comprises two disc parts 35, 37 of annular disc form arranged axially between the two fly-wheel discs 1, 11, which parts are held spaced and secured to one another by several cross-pieces 39. The disc part 35 adjacent to the fly-wheel disc 1 is secured thereto with rivets 41, as shown by Fig. 2. An inner disc part 43 of substantially annular disc form is arranged axially between the two outer disc parts 35, 37, rotatably in relation thereto. The disc part 43 is mounted rotatably on an annular bearing extension 49 connected with the fly-wheel disc 1 in the region of its internal circumference by means of a rolling body bearing formed in the example of embodiment as illustrated by two oblique ball bearings 45, 47 set against one another.Helical compression springs 57, which are resiliently stressed in the relative rotation of the disc part 43 for the one part and of the disc parts 35, 37 for the other part, are seated in windows 51 of the inner disc part 43 and windows 53 and 55, aligned therewith, of the outer side discs 35 and 37. The vibration damper comprises several such springs which are arranged in distribution in the circumferential direction substantially on the same diameter circle.

The inner disc part 43 extends out radially, outside the circle of arrangement of the springs 57, beyond the outer side discs 35, 37. In this radially outer region of the disc part 43 both the second fly-wheel disc 11 and the clutch cover 25 are screwed on by means of common screws 59. If in operation the flywheel disc 11 used as counter-presser plate is heated, the heat conduction from the flywheel disc 11 to the bearings 45, 47 can take place substantially only by the circuitous path by way of the disc part 43. Thus the bearing is thermally relieved. Furthermore the bearing is mechanically decoupled from the fly-wheel disc 11, so that temperature-caused distortions of the fly-wheel disc 11 have no effect upon the bearing.

The bearing extension 49 is held on the flywheel disc 1 with the same screws 3 with which the fly-wheel disc 1 is secured on the crank shaft 7. The screws 3 here pass through mutually aligned holes 61 and 63 in the flywheel disc 1 and the bearing extension 49 respectively. For the centring of the bearing extension 49 the fly-wheel disc 1 carries an annular shoulder 65 on its internal circumference. The bearing extension 49 carries an annular shoulder 67 which, together with the fly-wheel disc 11, axially fixes the inner race rings of the ball bearings 45, 47. The inner disc part 43 is provided on its internal circumference with an annular bearing flange 69 protruding axially towards the fly-wheel disc 11, which flange carries the disc part 43 nontiltably radially on the outer race rings of the ball bearings 45, 47.For the axial fixing of the disc part 43 a circlip 71 is inserted in a ring groove on the internal circumference of the bearing flange 69, and engages between the two outer race rings of the ball bearings 45, 47. The annular gap between the outer rings is of such deep dimensions that the circlip 71 can enter this groove in the fitting of the annular flange 69.

The torsional vibration damper 9 comprises several friction devices which come into use in a manner known per se in dependence upon the relative angle of rotation of the two flywheel discs 1, 11. A first friction device 73 is provided in the region of the bearing flange 69. It comprises a friction ring 75 arranged axially between the fly-wheel disc 1 and the disc part 43, an annular presser plate 77 arranged axially between the friction ring 75 and the disc part 43 and a dished spring 79 braced in between the presser plate 77 and the disc part 43. While the friction device 73 is effective at every relative angle of rotation of the fly-wheel discs 1, 11, a friction device 81 becomes effective only after exceeding of a pre-determined angle of relative rotation between the two fly-wheel discs 1, 11.The friction device 81 comprises a control disc 83 arranged axially between the disc parts 35, 43 and the control arms 85 of which in the usual way limit the angle of action of the friction device 83, also a thrust disc 87 arranged axially between the disc parts 37, 43.

The thrust disc 87 can if desired likewise be formed as control disc. The control disc 83 carries axial tabs 89 which extend through the windows 51 of the disc part 43. Between the free ends of the tabs 89 and the thrust disc 87 a dished spring 91 is braced which presses the control disc 83 against the disc part 35 and the thrust disc 87 against the disc part 37 to generate a friction torque.

Other forms of embodiment of friction devices can alternatively be provided.

Finally it should be mentioned that the flywheel disc 1 carries a starter toothed ring 93.

Fig. 3 shows a variant of the motor vehicle friction disc clutch which differs from the clutch according to Fig. 1 essentially in the nature of the securing of the under-load vibration damper and in an additional idling vibration damper of its clutch disc, which damper is dimensioned for idling operation.

The motor vehicle friction disc clutch ac cording to Fig. 3 again comprises a first flywheel disc 101 of substantially annular disc form which is secured with screws 103 in the region of its internal circumference on a crank-shaft 107, rotating about the axis 105 of rotation, of the internal combustion engine (not otherwise shown) of the motor vehicle. A second fly-wheel disc 111 is rotationally elastically coupled with the first fly-wheel disc 101 through an under-load torsional vibration damper 109 dimensioned for operation under load. On the side axially remote from the first fly-wheel disc 101 there is arranged a presser plate 11 3 which is guided in the usual way fast in rotation but axially displaceably on the second fly-wheel disc 111 utilised as counterpresserplate, for example by means of tangential straps or the like (not illustrated further).

Axially between the presser plate 11 3 and the second fly-wheel disc 111 there can be clamped friction linings 11 5 of a clutch disc 11 7, the hub 11 9 of which is coupled fast in rotation but axially displaceably through a toothing 121 with a gear input shaft 123 of a motor vehicle gearing (not illustrated further).

With the second fly-sheel disc T11 there is further connected a clutch cover 125 grasping over the clutch disc 11 7 and the presser plate 113, on which cover a diaphragm spring 1 29 is supported through support rivets 127. The diaphragm spring 1 29 lies with its external circumference upon noses 131 of the presser plate 11 3 and presses the presser plate 11 3, through the friction linings 11 5, against the second fly-wheel disc 111.For the disengagement of the clutch, tongues 1 33 of the diaphragm spring 1 29 are moved by means of a release system (not shown) in the direction towards the second fly-wheel disc 111, whereby the presser plate 11 3 is relieved and lifted away from the clutch disc 11 7.

The vibration damper which couples the two fly-wheel discs 101, 111 rotationally elastically with one another is dimensioned exclusively for operation under load. The hub 11 9 of the clutch disc 11 7 is radially divided, as will be explained in greater detail below, and the two parts are coupled rotationally elastically with one another through a vibration damper 1 34 dimensioned for idling operation.

Due to the division of the two vibration damper systems into the fly-wheel formed by the two fly-wheel discs 101, 111 for the one part and the clutch disc 11 7 for the other part, both vibrarion damper systems can be dimensioned optimally according to their operational ranges. The springs of the under-load vibration damper 109 can be arranged with relatively great radial spacing from the axis 105 of rotation, preferably at the radial distance of the clutch friction linings 11 5 or radially outside the linings.Comparatively abundant space is available for the accommodation of the idling vibration damper 1 34. The clutch disc 11 7 has very low weight and inertia moment, compared with conventional clutch discs with torsional vibration damping, so that synchronisation devices of the motor vehicle gearing are comparatively little stressed. The spring rating of the idling vibration damper can be very small, and lie in the order of magnitude of 0.1 to 0.3 Nm/degree.

The torsional vibration damper 109 comprises two disc parts 135, 137 of annular disc form arranged axially between the two fly-wheel discs 101, 111, which parts are held spaced and secured to one another by way of several cross-pieces 1 39. The disc part 1 35 adjacent to the fly-wheel disc 1 carries on its internal circumference a toothing 141 by means of which it is coupled fast in rotation with the fly-wheel disc 101, in a manner explained below. An inner disc part 143 of substantially annular disc form is arranged axially between the two outer disc parts 135, 137, rotatably in relation to these.

The disc part 143 is rotatably mounted, in the region of it internal circumference, through a ball bearing 145 on an annular bearing extension 149 connected with the fly-wheel disc 101. Helical compression springs 1 57 which are resiliently stressed in the relative rotation of the disc part 143 on the one hand and the disc parts 135, 1 37 on the other, are seated in windows 151 of the disc part 143 and windows 1 53 and 155, aligned therewith, of the outer disc parts 1 35 and 1 37 respectively. The under-load vibration damper 109 comprises a plurality of such springs 157 which are arranged in distribution in the circumferential direction substantially on the same diameter circle.

The inner disc part 143 protrudes radially outside the circle of arrangement of the springs 1 57 beyond the outer side discs 135, 1 37. In this radially outer region of the disc part 143 both the second fly-wheel disc 111 and the clutch cover 1 25 are screwed on by means of common screws 1 59. In Fig. 3 this region and the screws 1 59 are entered in chain lines, since this region is offset in angle about the axis 105 of rotation in relation to the section plane represented in Fig. 3 in solid lines. If the fly-wheel disc 111 utilised as counter-pressure plate is heated in operation, the heat conduction from the fly-wheel disc 111 to the bearing 145 can take place essentially only by the circuitous path by way of the disc part 143. The bearing 145 is thus thermally relieved. The bearing is furthermore mechanically decoupled from the fly-wheel disc 111, so that temperature-caused distortions of the fly-wheel disc 111 do not take effect upon the bearing.

The bearing extension 149 is held on the fly-wheel disc 101 with the same screws 103 with which the fly-wheel disc 101 is secured on the crank-shaft 107. The screws 103 in this case pass through mutually aligned holes 161 and 163 in the fly-wheel disc 101 and the bearing extension 149 respectively. For the centring of the bearing extension 149 the fly-wheel disc can carry an annular shoulder (not shown further) on its internal circumference. The bearing extension 149 carries an annular shoulder 1 67 which, together with the fly-wheel disc 101 and a distance ring 168, fixes the inner race ring of the ball bearing 145 axially in relation to the fly-wheel disc 101.The disc part 143 is provided on its internal circumference with an annular bearing flange 1 69 protruding axially towards the flywheel disc 111, which flange mounts the disc part 143 non-tiltably radially on the outer race rings of the ball bearings 145. For the axial fixing of the disc part 143 a circip 171 engages in a ring groove on the internal circumference of the bearing flange 1 69. The circlip 1 71 is seated in an outer ring groove of the outer race ring of the ball bearing 145, the depth of which is so dimensioned that the circlip can completely enter the outer ring groove in the fitting of the annular flange 169.

The under-load torsional vibration damper 109 comprises several friction devices which come into action in a manner known per se in dependence upon the relative angle of rotation of the two fly-wheel discs 101, 111. A first friction device 1 73 is provided in the region of the bearing flange 1 69. It comprises a friction ring 1 75 arranged axially between the fly-wheel disc 101 and the disc part 143, an annular presser plate 1 77 arranged axially between the friction ring 1 75 and the disc part 143, and a dished spring 1 79 braced in between the presser plate 1 77 and the disc part 143. The presser plate 1 77 is coupled fast in rotation but axially displaceably with the disc part 143.While the friction device 1 73 is effective at every angle of relative rotation of the fly-wheel discs 101, 111, a friction device 181 becomes effective only after a pre-determined angle of relative rotation between the two fly-wheel discs 101, 111 has been exceeded. The friction device 181 comprises a control disc 183 arranged axially between the side discs 135, 143, the control arms 1 85 of which control disc in the usual way limit the angle of action of the friction device 1 83. They further comprise a thrust disc 187, possibly also formed as control disc, arranged axially between the disc parts 137, 143. The control disc 183 carries axial tabs 189 which engage through the windows 151 of the disc part 143.Between the free ends of the tabs 189 and the thrust disc 187 there is braced a dished spring 191 which presses the control disc 183 against the disc part 135 and the thrust disc 187 against the disc part 137, for the generation of a friction torque. Other forms of embodiment of friction devices can alternatively be provided. Finally it should be mentioned that the fly-wheel disc 1 carries a starter toothed rim 193.

The idling vibration damper 1 34 is arranged substantially completely in the region of the hub 119 of the clutch disc 117. The hub 11 9 comprises an inner hub part 1 95 of substantially sleeve form which coaxially encloses the gear input shaft 1 23 and carries on its inner periphery an internal toothing engaging fast in rotation but axially displaceably in the toothing 121.An outer hub part 197 forming the foot part of the clutch disc 11 7 and firmly connected with the latter carries on its internal circumference enclosing the hub part 1 95 an internal toothing 1 99 which engages in an external toothing 201 of the hub part 1 95 and couples the hub part 1 97 and thus the clutch disc 11 7 fast in rotation but with play in the circumferential direction with the hub part 1 95 and thus the gear input shaft 123.

The hub part 1 95 protrudes axially beyond the hub part 197 and carries a hub disc 203 fast in rotation on the side remote from the crank-shaft. Axially on both sides of the hub disc 203 there are arranged side discs 205, 207 which, as indicated at 209, are connected with one another into a fixed unit. The side disc 205 is seated fast on the hub part 197.In windows 211 of the hub disc 203 and windows 213, 215, aligned therewith, of the side discs 205, 207 there are seated helical compression springs 217 which are resiliently stressed in the relative rotation of the hub disc 203 on the one hand and the side discs 205, 207 on the other, and couple the clutch disc 11 7 rotationally elastically through the hub parts 197, 195 with the gear input shaft 1 23. The play between the toothings 199,201 of the hub parts 197, 195 limits the operating angle of rotation of the idling vibration damper 1 34. After the rotational play is taken up the vibration damper 1 34 is bridged over and the under-load vibration damper 109 exclusively is effective.

The external diameter of the hub disc 203 and the side discs 205, 207 is made smaller than the internal diameter of the disc part 143, to reduce the weight and inertia moment of the clutch disc 11 7. The idling vibration damper 1 34 can comprise an additional friction device; at low friction torques the friction between the side discs 205, 207 and/or the hub disc 203 and/or the hub parts 195, 197 and also the internal friction of the toothings 199, 201 can suffice.

The internal toothing 141 of the disc part 1 35 engages in an external toothing, open towards the fly-wheel disc 101, of the bearing extension 149. In this way the under-load vibration damper 109 can be produced separately and secured together with the fly-wheel disc 101 in the fitting of the clutch. Likewise the fly-wheel disc 111, the clutch disc 117, the presser plate 11 3 and the clutch cover 125 with diaphragm spring 129 secured thereto can be pre-assembled and screwed to the disc part 143 in final assembly. Assembly is considerably facilitated by these measures.

Claims (14)

1. Motor vehicle friction disc clutch, comprising: a) two fly-wheel discs (1, 11; 101, 111)of substantially annular disc form, of which a first fly-wheel disc (1; 101) is formed in the egion of its internal circumference for securing to a crank-shaft (7; 107) of an internal combustion engine and of which a second flywheel disc (11; 111) is arranged coaxially beside the first fly-wheel disc (1; 101) and is rotatable about a common rotation axis (5; 105) in relation to the first fly-wheel disc (1; 101) b) a vibration damper (9; 109) coupling the two fly-wheel discs (1, 11; 101, 111) rotationally elastically with one another, having two annular outer disc parts (35, 37; 135, 137) arranged axially between the flywheel discs (1,11; 101,111) and connected with one another into one unit, an inner disc part (43; 143) rotatable in relation to the outer disc parts (35, 37; 135, 137) axially between the outer disc parts (35, 37; 135, 137), and having several springs (57; 157) retained in windows (51, 53, 55; 151, 153, 155) of the disc parts (35, 37, 43; 135, 137, 143) and resiliently stressable in the relative rotation of the outer disc parts (35, 37; 135, 137) and the inner disc parts (43; 143), c) a clutch cover (25; 125) arranged on the side of the second fly-wheel disc (11; 111) axially remote from the first fly-wheel disc (1; 101) and secured to the second fly-wheel disc (11; 111), d) a presser plate (13; 11 3) arranged on the side of the second fly-wheel disc (11; 111) axially remote from the first fly-wheel disc (1; 101) and connected fast in rotation but axially movably with the second fly-wheel disc, e) a clutch disc (17; 11 7) provided with clutch friction linings (15; 11 5) and arranged axially between the presser plate (13; 113) and the second fly-wheel disc (11; 111), f) a clutch spring device (29; 129) acting between the clutch cover (25; 125) and the presser plate (13; 11 3) and clamping in the clutch disc (17; 117) between the presser plate (13; 113) and the second fly-wheel disc (11; 111), characterised in that the two outer disc parts (35, 37; 135, 137) are connected fast in rotation with the first fly-wheel disc (1; 101), in that the inner disc part (43; 143) is mounted rotatably on the first fly-wheel disc (1; 101), in relation to the axis (5; 105) of rotation radially within the springs (57; 157) of the vibration dampers (9; 109), and in that the second fly-wheel disc (11; 111) is secured, in relation to the axis (5; 105) of rotation, radially outside the springs (57; 157) of the vibration damper (9, 109) on the inner disc part (43; 143).

2. Friction disc clutch according to Claim 1, characterised in that the inner disc part (43; 143) is mounted rotatably on an annular bearing extension (49; 149) separate from the first fly-wheel disc (1; 101) and detachably connected with the first fly-wheel disc (1; 101).

3. Friction disc clutch according to Claim 2, characterised in that the first fly-wheel disc (1) comprises centring elements for the centring of the bearing extension (49) in relation to the first fly-wheel disc (1).

4. Friction disc clutch according to Claim 2 or 3, characterised in that the first fly-wheel disc (1; 101) and the bearing extension (43; 143) comprise mutually aligned holes (61, 63; 161, 163) for the passage of common screws (3; 103) for securing to the crank-shaft (7; 107).

5. Friction disc clutch according to one of Claims 2 to 4, characterised in that the inner disc part (43; 143) is fixed axially on the bearing extension (49; 149).

6. Friction disc clutch according to one of Claims 1 to 5, characterised in that the clutch cover (25; 125) and the second fly-wheel disc (11; 111) are screwed on by means of common screws (59; 159) in the region of the external circumference of the inner disc part (43; 143).

7. Friction disc clutch according to one of Claims 1 to 6, characterised in that the side disc (35) axially adjacent to the first fly-wheel disc (1) is riveted to the first fly-wheel disc (1).

8. Friction disc clutch according to one of Claims 1 to 6, characterised in that the inner disc part (143) is rotatably mounted on a bearing extension (149) protruding from the first fly-wheel disc (101) axially towards the second fly-wheel disc (111) and in that the bearing extension (149) comprises an external toothing (225) and at least one of the side discs (135) comprises on its internal circumference an internal toothing (141) engaging fast in rotation in the external toothing (225).

9. Friction disc clutch according to one of Claims 1 to 8, characterised in that the inner disc part (43; 143) comprises on its internal circumference an axially protruding bearing flange (69; 169) mounted axially fixedly on the bearing extension (49; 149).

10. Friction disc clutch according to one of Claim 1 to 9, characterised in that the vibration damper (9; 109) is dimensioned for operation under the load and comprises a friction damper (73, 81; 173, 181) dimensioned for operation under load, in that the clutch disc (17, 11 7) comprises a hub part (195) and a disc part of annular disc form carrying the clutch friction linings (11 5) and mounted on the hub part (195) rotatably through a limited angle of rotation in relation to the hub part (195), and in that the disc part and the hub part (195) are rotationally elastically coupled with one another through a second vibration damper (134) dimensioned for idling operation.

11. Friction disc clutch according to Claim 10, characterised in that the hub part (195) has an external toothing (201) on its external circumference, in that the disc part carries on its internal circumference a foot part (197) provided with an internal toothing (199) and is coupled through the internal toothing (199) fast in rotation but with play in the circumferential direction with the hub part (195) and in that the idling vibration damper (134) is secured to the hub part (195) and the foot part (197).

1 2. Friction disc clutch according to Claim 11, characterised in that the hub part (195) protrudes axially beyond the foot part (197) and carries a hub disc (203) axially laterally of the foot part (197), in that axially on each of the two sides of the hub disc (203) there is arranged one of two side discs (205, 207) of annular disc form connected into one unit, in that one of the side discs (205) is secured to the foot part (197) and in that several springs (217) of the idling vibration damper (134), which are resiliently stressed on a relative rotation of the hub part (195) and the foot part (197), are arranged in windows (211, 213, 215) of the hub disc (203) end of the side discs (205, 207).

1 3. Friction disc clutch according to Claim 12, characterised in that the external diameter of the hub disc (203) and of the side discs (205, 207) of the idling vibration damper (134) is smaller than the internal diameter of the inner disc part (143) of the under-load vibration damper (109).

14. Motor vehicle friction disc clutch as claimed in claim 1 and substantially as herein described with reference to and as illustrated by any one of the examples shown in the accompanying drawings.