Abstract:
A torque transmission device for a drive train of a motor vehicle driven by an internal combustion engine. The device includes an input part and an output part having a common axis of rotation around which the input part and the output part are jointly rotatable relative to one another, and a spring damper arrangement that has at least one energy storage device. A friction device is effective between the input part and the output part and is arranged radially outside the at least one energy storage device, in order to provide a torque transmission device having a construction that is optimized with respect to the installation space.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of International Application Serial No. PCT/DE2012/000754, having an international filing date of 26 Jul. 2012, and designating the United States, the entire contents of which are hereby incorporated by reference to the same extent as if fully rewritten. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a torque transmission device, in particular for a drive train of a motor vehicle driven by an internal combustion engine. The device includes an input part and an output part having a common axis of rotation, around which the input part and the output part are jointly rotatable and twistable relative to one another to a limited degree, and a spring damper arrangement that has at least one energy store and a friction device and is effective between the input part and the output part. 
         [0004]    2. Description of the Related Art 
         [0005]    DE 10 2009 035 916 A1 discloses a torsional vibration damper, in particular a dual mass flywheel, including a primary mass and a secondary mass that are coupled to each other with respect to relative rotation between the two by a friction device, which friction device includes a support plate, a support disc, and a diaphragm spring, and wherein multiple tabs are arranged on the inner circumference of the diaphragm spring to improve the centering of the friction device during assembly of the friction device. 
         [0006]    In accordance with DE 10 2009 035 916 A1, the dual mass flywheel includes a primary mass and a secondary mass that are rotatable relative to each other against the force of an arc spring assembly. The dual mass flywheel has an axis of rotation. The secondary mass includes arcuate cutouts in which the arc spring assembly is supported. The primary mass has channel-like arcuate expansions in which the arc spring assembly is situated. 
         [0007]    In accordance with DE 10 2009 035 916 A1, the friction device damps the relative rotation between the primary mass and the secondary mass by dry friction. The damping device includes a support plate that is firmly connected, for instance riveted, to the primary mass, and a support disc that is fixed with respect to rotation about the axis of rotation relative to the support plate, but is displaceable in the axial direction relative to the support plate. A friction control disc is arranged between the support plate and the support disc. The friction control disc is connected to the secondary mass by teeth so as to be axially displaceable and fixed against relative rotation. The friction control disc is in surface contact with the support plate and with the support disc. Thus rotation of the friction control disc relative to the support plate and relative to the support disc is possible against the dry friction between the contacting surfaces. The support disc is pressed onto the friction control disc and the support plate, respectively, by a diaphragm spring, causing the friction control disc to be clamped between the support plate and the support disc. Fingers of the support disc pass through corresponding openings in the support plate. Likewise, fingers of the diaphragm spring pass through openings of the support plate. 
         [0008]    The present invention has as an object providing a torque transmission device of the kind described above having a design that is adapted to/optimized in terms of the installation space. 
       SUMMARY OF THE INVENTION 
       [0009]    In accordance with one aspect of the present invention, the object identified above is attained by a torque transmission device, in particular for a drive train of a motor vehicle driven by an internal combustion engine, including an input part and an output part having a common axis of rotation around which the input part and the output part are each rotatable and are rotatable relative to one another to a limited degree. The device includes a spring damper arrangement that has at least one energy store and a friction device and is effective between the input part and the output part, wherein the friction device is arranged radially outside the at least one energy store. 
         [0010]    The terms “input part” and “output part” refer to a torque flow direction starting from a drive device such as an internal combustion engine. “Radial” refers to the axis of rotation. A radial direction is a direction perpendicular to the axis of rotation. 
         [0011]    The torque transmission device can be a torsional vibration damper. The torque transmission device can be a dual mass flywheel. The input part of the torque transmission device can be in driving connection with an output part of the internal combustion engine, in particular to a crankshaft. The output part of the torque transmission device can be in driving connection with an input part of a friction clutch, in particular a clutch cover. 
         [0012]    The spring damper arrangement can include a spring device. The spring damper arrangement can include a damper device. The spring device and the damper device of the spring damper arrangement can be connected in parallel. The spring device can include at least one energy store. The spring device can include at least one spring. The at least one spring of the spring device can be a coil spring. The at least one spring of the spring device can be a compression spring. The at least one spring of the spring device can be an arc-shaped coil spring. The spring device can include multiple springs, in particular two springs. The springs of the spring device can be arranged around the axis of rotation in an arc-like way. The springs of the spring device can be arranged around the axis of rotation and can be spaced from the axis of rotation by a first radius. The damper device can include the friction device. The friction device can be arranged around the axis of rotation in an annular way. The friction device can be arranged around the axis of rotation and spaced from the axis of rotation by a second radius. The second radius can be greater than the first radius. 
         [0013]    The torque transmission device of the invention requires less installation space in the region of the axis of rotation. A reduced normal force or pressing force is required on the friction device. A surface pressure on the friction device is reduced. The friction device is subject to a lower degree of stress. 
         [0014]    A pendulum mass carrier part of a centrifugal pendulum device can be connected to the output part to co-rotate with the latter, and the friction device can be effective between the input part and the pendulum mass carrier part. The output part can have a flange part. The output part can include an inertial mass part. The inertial mass part can be firmly connected to the flange part of the output part. The inertial mass part can be riveted to the flange part of the output part. The pendulum mass carrier part can be firmly connected to the inertial mass part. The pendulum mass carrier part can be riveted to the inertial mass part. The pendulum mass carrier part can be rotatable about the axis of rotation together with the output part. The pendulum mass carrier part can have a flange-like shape. The pendulum mass carrier part can have a double-flange shape, including two flange sections that are spaced from each other in the direction of the axis of rotation. At least one pendulum mass that is displaceable relative to the pendulum mass carrier part under the influence of centrifugal forces can be arranged on the pendulum mass carrier part. The at least one pendulum mass can be displaceable along a defined path. The at least one pendulum mass can be displaceable between a first end position and a second end position. The at least one pendulum mass can be arranged on the pendulum mass carrier part to be displaceable with the aid of pendulum rollers. The at least one pendulum mass and/or the pendulum mass carrier part can include pendulum mass roller tracks in which the pendulum masses are arranged. The at least one pendulum mass can be arranged between the two flange sections of the pendulum mass carrier part. 
         [0015]    The friction device can include a friction control disc that is in frictional engagement with the input part and connected to the pendulum mass carrier part in a positive-locking way. The friction control disc can include at least one friction surface that frictionally corresponds with the input part. The friction control disc can be of one-piece construction. The friction control disc can be of multipartite construction. Multiple friction control disc parts can be interconnected by a carrier part. The friction control disc or friction control disc parts can include a friction material. The friction material can be a plastic material. The friction material can be flexible, rubber resin bound, elastomeric resin bound, injection-molded, and/or metal-free. The carrier part can be a sheet metal part. The carrier part can have through holes in which the friction control disc parts are received. Thus, the friction control disc can be entrained by the pendulum mass carrier part in a positive locking way, and a frictional relative movement between the friction control disc and the input part is possible. Friction material is saved. The carrier plate facilitates the assembly of the friction elements. 
         [0016]    The input part can include a flange part and a cover part, and the friction control disc can be in frictional engagement with the cover part. The flange part can be used as a driving connection between the torque transmission device and the internal combustion engine. The cover part can be firmly connected to the flange part. The cover part can be connected to the flange part in a material-locking way. The cover part and the flange part can be welded to each other. The cover part can be arranged between the flange part and the pendulum mass carrier part, as viewed in the direction of the axis of rotation. The cover part can include a friction surface in frictional contact with the friction control disc. The friction surface of the cover part can face the pendulum mass carrier part. The friction surface of the cover part can face away from the pendulum mass carrier part. A frictional engagement between the friction control disc and the cover part can occur in a plane that is perpendicular to the axis of rotation. The friction control disc can be in frictional engagement with the flange part. A frictional engagement between the friction control disc and the flange part can occur in a plane that is parallel to the axis of rotation. 
         [0017]    The friction device can include a friction control disc that is connected to the input part in a positive locking way, and in frictional engagement with the pendulum mass carrier part. The pendulum mass carrier part can be arranged between the input part and the inertial mass part of the output part, as viewed in the direction of the axis of rotation. The pendulum mass carrier part can include a friction surface in frictional correspondence with the friction control disc. The friction surface of the pendulum mass carrier part can face the input part. Thus, the friction control disc can be entrained by the input part in a positive-locking way, and a frictional relative movement between the friction control disc and the pendulum mass carrier part can occur. The input part can include a flange part and a cover part, and the friction control disc can be connected to the cover part in a positive-locking way. 
         [0018]    The cover part can have a flange section arranged radially outside the at least one energy store, and the friction device can be arranged on the flange section. The cover part can include a connecting section for connection with the flange part of the input part. The connecting section of the cover part can be arranged radially inside the flange section. The cover part together with the flange part of the input part can delimit a receiving space for the at least one energy store. The receiving space can have a torus-like shape. The receiving space can be arranged radially inside the flange section. The receiving space can be arranged radially inside the connecting section of the cover part. The friction device can frictionally correspond to the flange section. 
         [0019]    First stop portions that are effective in a first direction of rotation and second stop portions that are effective in a second direction of rotation can be provided for connecting the friction control disc in a positive-locking way, and the friction control disc can have entrainment sections corresponding to the stop portions. In the first direction of rotation, the entrainment portions can engage with the first stop sections. In the second direction of rotation, the entrainment portions can engage with the second stop portions. The entrainment portions can engage with the stop portions in the circumferential direction of the friction control disc. Thus different stop portions are effective in each direction of rotation. The stop portions can have recesses. The recesses can have marginal-portions. The marginal portions can form the stop portions. The entrainment portions can be provided with extensions. The extensions can be received in the recesses. The extensions can extend into the recesses in the direction of the axis of rotation. The friction control disc can have multiple entrainment portions distributed in the circumferential direction. The friction control disc can include multiple extensions distributed in the circumferential direction. The extensions can be evenly distributed in the circumferential direction. 
         [0020]    In accordance with a further embodiment, for the positive connection, the friction control disc can have the stop portions and the pendulum mass carrier part can have the entrainment-portions. The entrainment portions can be riveting heads of a riveting of the pendulum mass carrier part. 
         [0021]    The stop portions can be spaced from the entrainment portions in such a way that hysteresis independent of the direction of rotation is created. The stop portions can be spaced from the entrainment portions in the circumferential direction of the friction control disc. The friction control disc can have recesses shaped like elongated holes. The friction control disc can have multiple recesses distributed along the circumferential direction. Each of the recesses can extend in the circumferential direction of the friction control disc. The recesses can have a shape that is curved in correspondence with the circumference of the friction control disc. Each recess can include a first stop portion and a second stop portion. Each recess can include a first end portion and a second end portion. The first end portions of the recesses can form the first stop portions. The second stop portions of the recesses can form the second stop portions. In the entrainment direction the recesses can be larger than the entrainment portions. The entrainment portions can be guided in the recesses. The lengths of the recesses in the entrainment direction can define a predetermined clearance angle. A “clearance angle” is a maximum angular range through which the input part and the output part can be rotated relative to each other upon a change of the direction of rotation, without any entrainment between the stop portions and the entrainment portions, and thus without friction on the friction control disc. 
         [0022]    The friction device can include a spring device for loading the friction control disc, and the spring device can be in immediate frictional contact with the friction control disc. The spring device can apply a force or force component in the direction of the axis of rotation. The spring device can apply a normal force to the friction device to generate a frictional force. The spring device can include a diaphragm spring. The spring device can form a support plate. The spring device can have a dual function. A separate support plate can be dispensed with. In this context, a support plate is, in particular, understood to be an element that is displaceable in the direction of the axis of rotation and rotatable relative to the friction control disc, and is used to transmit a pressing force to the friction control disc. The support plate can be connected for co-rotation with the input part, or with the pendulum mass support part. 
         [0023]    The friction control disc can cover the pendulum mass carrier part in such a way that the pendulum rollers are fixed. Thus, separate position-securing means for the pendulum rollers can be dispensed with. 
         [0024]    In summary, and in other words, among other aspects, the invention relates to a friction device for a dual mass flywheel including a centrifugal pendulum, wherein the friction device is arranged radially above an arc spring channel. The friction device can be mounted between a cover and a primary mass disc. Actuation of the friction device can take place through an elongated hole on a centrifugal pendulum flange. The width of the elongated hole can define a clearance angle of the friction control disc. Due to the radial position (far outward), an axial force of a diaphragm spring, and thus the surface pressure on the friction control disc, can be reduced and a favorable material can be used for the friction control disc. 
         [0025]    The friction device can be mounted to the centrifugal pendulum flange. In that case, the friction control disc can be actuated through a recess in the cover. The diaphragm spring for introducing the axial force into the friction control disc can additionally be used as a support plate. To prevent cylinder rollers from falling out of the centrifugal pendulum, the friction control disc can be placed above roller tracks. The friction control disc can be divided into multiple elements to save plastic material. To simplify the positioning of the various individual elements during assembly, they can be assembled in a carrier plate. The friction device can be riveted to the circumference of the cover with multiple lugs. Thus, no additional rivets need to be used during assembly. The friction control disc can be mounted to a cover side. The friction control disc can be divided into multiple individual elements and mounted to a carrier plate. The carrier plate can be used to actuate the friction device through additional ears on the circumference. The diaphragm spring can also act as a cover disc to create a second friction surface. The diaphragm spring can act as a cover disc. The area of contact on the outer diameter of the friction control disc and on the cover can provide an additional friction surface. Thus, even under the influence of centrifugal forces, the friction control disc can be prevented from widening too much. Multiple tabs on the friction control disc can pass through a recess in the cover and into an elongated hole in the centrifugal pendulum flange, and can thus allow the friction device to be actuated. The friction control disc can be actuated through the closing head of a rivet connection centrifugal pendulum/secondary flywheel. 
         [0026]    In the following description, exemplary embodiments of the invention will be described in more detail with reference to drawing figures. Further features and advantages will become apparent from the description. Concrete features of these exemplary embodiments may can represent general features of the invention. Features of these exemplary embodiments that are connected to other features may can represent individual features of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    The diagrammatic drawings include by way of example: 
           [0028]      FIG. 1  illustrating two cross-sectional views of a dual mass flywheel including an input part, an output part, a spring damper device including arc-shaped springs, a friction device arranged radially outside the arc-shaped springs, and including a friction control disc and a centrifugal pendulum device with a pendulum mass carrier part, wherein the friction control disc is in frictional engagement with the input part and is connected to the pendulum mass carrier part in a positive-locking way; 
           [0029]      FIG. 2  illustrating a cross-sectional view of a dual mass flywheel including an input part, an output part, a spring damper device including arc-shaped springs, and a friction device arranged radially outside the arc-shaped springs and including a friction control disc and a centrifugal pendulum device with a pendulum mass carrier part, wherein the friction control disc is non-rotatably connected with the input part in a positive-locking way and is in frictional engagement with the pendulum mass carrier part; 
           [0030]      FIG. 3  illustrating a cross-sectional view of a dual mass flywheel including an input part, an output part, a spring damper device including arc-shaped springs, and a friction device arranged radially outside the arc-shaped springs and including a friction control disc and a centrifugal pendulum device with a pendulum mass carrier part, wherein the friction control disc is embodied as a carrier plate with friction elements; 
           [0031]      FIG. 4  illustrating a cross-sectional view of a dual mass flywheel including an input part, an output part, a spring device including arc-shaped springs, and a friction device arranged radially outside the arc-shaped springs and including a friction control disc and a centrifugal pendulum device with a pendulum mass carrier part, wherein the friction control disc is held by a diaphragm spring riveted to the input part; 
           [0032]      FIG. 5  illustrating a cross-sectional view of a dual mass flywheel including an input part, an output part, a spring device including arc-shaped springs, and a friction device arranged radially outside the arc-shaped springs and including a friction control disc and a centrifugal pendulum device with a pendulum mass carrier part, wherein the friction control disc is embodied as a carrier plate with friction elements that are effective on two sides; 
           [0033]      FIG. 6  illustrating a cross-sectional view of a dual mass flywheel including an input part, an output part, a spring device including arc-shaped springs, and a friction device arranged radially outside the arc-shaped springs and including a friction control disc and a centrifugal pendulum device with a pendulum mass carrier part, wherein a diaphragm spring is provided as a support plate; and 
           [0034]      FIG. 7  illustrating a cross-sectional view of a dual mass flywheel including an input part, an output part, a spring device including arc-shaped springs, and a friction device arranged radially outside the arc-shaped springs and including a friction control disc and a centrifugal pendulum device with a pendulum mass carrier part, wherein a positive connection is established between the friction control disc and the pendulum mass carrier part with the aid of rivets. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]      FIG. 1  depicts two cross-sectional views of a dual-mass flywheel  100  including an input part  102 , an output part  104 , a spring damper device with arc-shaped coil springs such as  106 , a friction device arranged radially outside the arc-shaped springs  106 . The dual-mass flywheel includes a friction control disc  108  and a centrifugal pendulum device with a pendulum mass carrier part  110 , wherein the friction control disc  108  is in frictional engagement with the input part  102  and is connected to the pendulum mass carrier part  110  in a positive-locking way. The left part of  FIG. 1  is a cross-sectional view along the axis of rotation  112  of the dual mass flywheel  100 . The right part of  FIG. 1  is a sectional view along line Z-Z of the left part of  FIG. 1 . 
         [0036]    The dual mass flywheel  100  is an example of a torque transmission device and is a torsional vibration damper. The dual mass flywheel  100  acts to damp torsional vibrations in an otherwise non-illustrated drive train of a motor vehicle that is driven by an internal combustion engine. Such torsional vibrations are in particular caused by periodic combustion processes in the internal combustion engine and the resultant irregular rotational speed of the crankshaft. 
         [0037]    The input part  102  of the dual mass flywheel  100  can be connected with an output shaft of the combustion engine, in particular with a crankshaft, in a way to transmit torque. The output part  104  of the dual mass flywheel  100  can be connected to an input part of a friction clutch in a torque-transmitting way. The input part  102  and the output part  104  are jointly rotatable about the common axis of rotation  112  and are rotatable relative to each other about the axis of rotation  112  to a limited degree. 
         [0038]    The input part  102  includes a flange part  114  and a cover part  116 . The flange part  114  and the cover part  116  are firmly connected to each other; in the present example they are welded together. The flange part  114  and the cover part  116  axially abut a receiving space  118  that is of torus-like shape. The output part  104  includes a flange part  120 , and an inertial mass part  122  is firmly connected, for instance riveted, to the flange part  120 . The inertial mass part  122  of the output part  104  is rotatably supported on the flange part  114  of the input part  102 . The pendulum mass carrier part  110  of the centrifugal pendulum device is firmly connected, preferably riveted, to the inertial mass part  122 . In a double-flange-like way, the pendulum mass carrier part  110  is formed with two flange sections arranged to be next to each other and spaced apart as viewed in the direction of the axis of rotation  112 . Pendulum masses such as  124  are arranged between the flange sections of the pendulum mass carrier part  110 . 
         [0039]    The pendulum masses  124  are arranged on the pendulum mass carrier part  110  so as to be displaceable relative to the pendulum mass carrier part  110 . The pendulum masses  124  are pivotable. The pendulum masses  124  are arranged on the pendulum mass carrier part  110  so as to be spaced apart from the axis of rotation  112 . The pendulum masses  124  are displaceable on a defined path and between two end positions. In the present example, the centrifugal pendulum device includes three pendulum masses  124 . In accordance with another embodiment, the centrifugal pendulum device can include more or fewer pendulum masses, for example two or four pendulum masses. The pendulum mass carrier part  110  is arranged between the cover part  116  of the input part  102  and the inertial mass part  122  of the output part  104  as viewed in the direction of the axis of rotation  112 . 
         [0040]    The pendulum mass carrier part  110  has through holes such as  126  corresponding to through holes of the pendulum masses  124 . Pendulum rollers such as  128  for supporting the pendulum masses  124  in a way to be displaceable along a defined path between the two end positions of through holes  126  are arranged in the through holes  126  of the pendulum mass carrier part  110  and the through holes of the pendulum masses. 
         [0041]    The spring damper device is effective between the input part  102  and the output part  104 . The spring damper device includes arc-shaped coil springs  106 . In the present example, there are two arc-shaped coil springs  106 , each of which extends along an approximately semicircular circumferential section of receiving space  118 . On one side, the arc-shaped springs  106  are supported on the input part  102 ; on the other side, the arc-shaped springs  106  are supported on the flange part  120  of the output part  104 . 
         [0042]    Radially inwardly, the flange part  114  of the input part  102  has a portion that extends in the direction of the axis of rotation  112  and underlies a radially inner portion of the centrifugal pendulum device. Radially outwardly, the cover part  116  of the input part  102  has a flange portion  130 . As viewed in the direction of the axis of rotation  112 , the flange portion  130  of the cover part  116  is radially spaced from the flange part  114  of the input part  102 , forming a receiving space between flange part  114  of input part  102  and flange section  130  of cover part  116 . That receiving space receives the friction device of the spring damper device. 
         [0043]    The friction device includes the friction control disc  108 , a support plate  132 , and a diaphragm spring  134 . The support plate  132  is displaceable in the direction of the axis of rotation  112  to a limited degree. The friction control disc  108  is arranged between the flange section  130  of the cover part  116  and the support plate  132 . The diaphragm spring  134  is arranged between the flange part  114  and the support plate  132 . On one side, the diaphragm spring  134  is supported on the flange part  114  and on the other side the diaphragm spring  134  is supported on the support plate  132 . Thus the support plate  132  is loaded by the diaphragm spring in the direction of the friction control disc  108 . The diaphragm spring  134  generates a pressing force to press the friction control disc  108  between the flange section  130  of the cover part  116  and the support plate  132 . On the friction control disc  108 , the pressing force creates a normal force that, taking into account a coefficient of friction, results in a proportional frictional force. 
         [0044]    Facing the pendulum mass carrier part  110 , the friction control disc  108  includes entrainment portions such as  136 . In the present example, the friction control disc  108  includes two diametrically opposed entrainment portions  136 . In another embodiment, the friction control disc  108  can have more or fewer entrainment portions. The friction control disc  108  can include one, three, or four entrainment portions, for instance. In the present example, the entrainment portions  136  are formed as axial extensions of circular cross section. The flange portion of the pendulum mass carrier part  110  that is adjacent to the friction control disc  108  has engagement portions such as  138 ,  140 . The engagement portions  138 ,  140  are defined by respective end portions of elongated hole-like recesses such as  142  in the pendulum mass carrier part  110 . The recesses  142  have an arc-like shape corresponding in shape to the circumference of the friction control disc  108 . In the lengthwise direction, the recesses  142  extend over an angular range of approximately 30°-45°, in particular of approximately 36°. The width of the recesses  142  in the radial direction approximately corresponds to the radial height of entrainment portions  136 . In the present example, the pendulum mass carrier part  110  includes two diametrically opposed recesses  142 . In another embodiment, the pendulum mass carrier part  110  can have more or fewer recesses. For example the pendulum mass carrier part can have one, three, or four recesses. 
         [0045]    In the direction of the axis of rotation  112  the entrainment portions  136  of the friction control disc  108  extend into the recesses  142  of the pendulum mass carrier part  110 . The entrainment portions  136  are guided in the recesses  142 . As a function of the direction of rotation, the entrainment portions  136  can alternatingly hit the engagement portions  138 ,  140 . Thus, there is an angle-of-rotation region in which the input part  102  and the output part  104  can be rotated relative to each other without carrying along the friction control disc  108 . That angular range is also referred to as a clearance angle  144 . 
         [0046]    The bearing region between the inertial mass part  122  of the output part  104  and the flange part  114  of the input part  102  is arranged radially inward, relative to and facing the axis of rotation  112 . The connection between the flange part  120  and the inertial mass part  122  is arranged in the radially outward direction relative to axis of rotation  112 . Following even further outward in a radial direction are the receiving space  118  and the arc-shaped springs  106 . Following even further outward in a radial direction, the flange part  114  and the cover part  116  of the input part  102  are connected to each other. Following even further outward in a radial direction are the friction device and the centrifugal pendulum device. 
         [0047]      FIG. 2  is a cross-sectional view of a second embodiment of a dual-mass flywheel  200  including an input part  202 , an output part  204 , a spring damper device including arc-shaped coil springs  206 , and a friction device arranged radially outside the arc-shaped springs  206 . The friction device includes a friction control disc  208  and a centrifugal pendulum device with a pendulum mass carrier part  210 , wherein the friction control disc  208  is connected to the input part  202  in a positive-locking way and in frictional engagement with the pendulum mass carrier part  210 . The cover part  212  of the input part  202  includes recesses with stop portions in which the entrainment portions of the friction control disc  208  engage. The flange section  214  of the cover part  212  is bent towards the pendulum mass carrier part  210 . The recesses with the stop portions are arranged on that border of the cover segment  212  that is oriented toward the pendulum mass carrier part  210 . A diaphragm spring  216  is connected, in the present example riveted, to that flange portion of the pendulum mass carrier part  210  that faces the input part  202 . The diaphragm spring  216  simultaneously functions as a support plate. The friction control disc  208  covers that flange portion of the pendulum mass carrier part  210  that faces the input part  202  in such a way that pendulum rollers of the pendulum mass carrier element are prevented from falling out. The pendulum rollers of the centrifugal pendulum device are fixed with the aid of the friction control disc. For further functional details, refer in particular to  FIG. 1  and the associated description. 
         [0048]      FIG. 3  is a cross-sectional view of a third embodiment of a dual mass flywheel  300 , including an input part  302 , an output part  304 , a spring damper device including arc-shaped coil springs  306  and a friction device arranged radially outside the arc-shaped springs  306 . The friction device includes a friction control disc  308  and a centrifugal pendulum device with a pendulum mass carrier part  310 , wherein the friction control disc  308  is embodied as a carrier plate  312  with friction elements  314 . The carrier plate  312  is shaped like an annular disc and has recesses such as  316 . The friction elements  314  are inserted into the recesses  316 . The recesses  316  are shaped like elongated holes. Each friction element  314  has a friction portion  318  and an attachment portion  320 . For further functional details, refer in particular to  FIG. 1  and the associated description. 
         [0049]      FIG. 4  is a cross-sectional view of a dual mass flywheel  400 , including an input part  402 , an output part  404 , a spring damper device including arc-shaped coil springs  406 , and a friction device arranged radially outside the arc-shaped springs  406 . The friction device includes a friction control disc  408  and a centrifugal pendulum device with a pendulum mass carrier part  410 , wherein the friction control disc  408  is held by a diaphragm spring  412  riveted to the input part  402 . The diaphragm spring  412  simultaneously functions as a support plate  414 . The diaphragm spring  412  is connected, in the present example riveted, to a flange portion  416  of a cover part  418  of the input part  402 . The riveting is arranged on the radially outer marginal section of the flange portion  416 . For riveting purposes, pins  420  protruding towards the pendulum mass carrier part  410  are arranged on the marginal section of the flange portion  416 . The pins  420  are part of the flange portion  416 . For assembly purposes, the pins  420  are placed in through holes of the diaphragm spring  412  and the free ends of the pins  420  are deformed to connect the diaphragm spring  412  with the flange portion  416 . Thus, no separate rivets are required. Recesses with stop portions are provided on that flange portion of the pendulum mass carrier part  410  that faces the input part  402 . For further functional details, refer in particular to  FIG. 1  and the associated description. 
         [0050]      FIG. 5  is a cross-sectional view of a dual mass flywheel  500 , including an input part  502 , an output part  504 , a spring damper device including arc-shaped coil springs  506  and a friction device arranged radially outside the arc-shaped springs  506 . The friction device includes a friction control disc  508  and a centrifugal pendulum device with a pendulum mass carrier part  510 , wherein the friction control disc  508  is embodied as a carrier plate  512  with friction elements that are effective on two sides of carrier plate  512 . The carrier plate  512  is shaped like an annular disc and has recesses such as  514 . The friction elements are arranged in the recesses  514 . The recesses  514  are shaped like elongated holes. Each friction element includes two friction element parts  516 ,  518 . Each friction element part  516 ,  518  has a friction portion  520 ,  522  and an attachment portion  524 ,  526 . For assembly purposes, the attachment portions  524 ,  526  of the friction element parts  516 ,  518  are joined at the recesses  514  in such a way that they are held in the recesses  514 . Thus each friction element part  516 ,  518  has two respective friction sides  520 ,  522 . The friction control disc  508  is suitable for two-sided frictional contact. Recesses with stop portions are arranged on that flange portion of the pendulum mass carrier part  510  that faces the input part  502 . The carrier plate  512  has axial extensions directed toward the flange portion of the pendulum mass carrier part  510 . Those axial extensions define entrainment portions  528 . The diaphragm spring  530  simultaneously acts as a support plate  532 . For further functional details, refer in particular to  FIG. 1  and the associated description. 
         [0051]      FIG. 6  is a cross-sectional view of a dual mass flywheel  600 , including an input part  602 , an output part  605 , a spring damper device including arc-shaped coil springs  606 , and a friction device arranged radially outside the arc-shaped springs  606 . The friction device includes a friction control disc  608  and a centrifugal pendulum device with a pendulum mass carrier part  610 , wherein a diaphragm spring  612  is provided as a support plate  614 . Recesses with stop portions are provided on that flange portion of the pendulum mass carrier part  610  that faces the input part  602 . The pendulum mass carrier part  610  that faces input part  602  includes axially-directed portions  616  that protrude in the direction of the input part  602  in a tab-like manner. These sections  616  include the recesses with the stop portions. In the radial direction, the friction control disc  608  is in frictional contact with the flange part  618  of the input part  602 . Thus, movement of the friction control disc  608  under the influence of centrifugal forces can be limited or prevented. For further functional details, refer in particular to  FIG. 1  and the associated description. 
         [0052]      FIG. 7  is a cross-sectional view of a dual mass flywheel  700 , including an input part  702 , an output part  704 , a spring damper device including arc-shaped coil springs  706  and a friction device arranged radially outside the arc-shaped springs  706 . The friction device includes a friction control disc  708  and a centrifugal pendulum device with a pendulum mass carrier part  710 , wherein a positive connection is established between the friction control disc  708  and the pendulum mass carrier part  710  with the aid of rivets such as  712 . The rivets  712  act to connect the flange portions of the pendulum mass carrier part  710 , as well as of the pendulum mass carrier part  710 , with the inertial mass part  714  of the output part  704 . Each rivet  712  has a rivet head  716 , such as a closing head, directed towards the input part  702 . The rivet heads  716  form entrainment portions. The friction control disc  708  has recesses with stop portions. For further functional details, refer in particular to  FIG. 1  and the associated description.