Abstract:
A torque transmission device in the drive train of a motor vehicle for transmitting torque, which has a clutch, particularly a dual-clutch, and a support tube that extends in the axial direction towards a housing, essentially a gear mechanism housing, and is radially arranged within at least one actuator bearing, in particular two actuator bearings, as well as a bearing device for the clutch. Part of the clutch cover facing the housing is supported by the bearing device for the clutch.

Description:
This application is a continuation of PCT/DE2008/000058 filed Jan. 14, 2008, which in turn claims the priority of DE 10 2007 004 752.7 filed Jan. 31, 2007, the priority of both applications is hereby claimed and both applications are incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a torque transmission device in the drive train of a motor vehicle for the transmission of torque with a clutch, in particular a dual clutch, and a support tube which extends in the axial direction toward a housing, in particular a transmission housing, and radially within at least one actuating bearing, in particular two actuating bearings, for the clutch, and with a bearing device for the clutch. 
     There are various options to mount the clutch. It is known from German patent application publication DE 34 27 163 A1 to mount a centrifugal mass of a damping device via an anti-friction bearing on an axial projection which is provided on the housing of a transmission via an anti-friction bearing. The axial projection serves at the same time as a guide tube for a clutch operator. German patent application publication DE 34 27 171 A1 has disclosed a damping device, in which a centrifugal mass is mounted on an axial projection which is provided on a housing of an internal combustion engine. French patent application publications FR 2880932 A1 and FR 2879700 A1 have disclosed clutches which are mounted on the transmission side radially outside an actuating bearing of the clutch. US patent US 2006/0163019 A1 has disclosed the mounting of a clutch on a bearing sleeve which is connected to a transmission housing and extends radially between two actuating bearings. 
     It is an object of the invention to provide a torque transmission device by which torque transmission device the mounting of the clutch is improved. 
     SUMMARY OF THE INVENTION 
     The object is solved in a torque transmission device in the drive train of a motor vehicle for the transmission of torque with a clutch, in particular a dual clutch, and a support tube which extends in the axial direction toward a housing, in particular a transmission housing, and radially within at least one actuating bearing, in particular two actuating bearings, for the clutch, and with a bearing device for the clutch, by the fact that a clutch cover part which faces the housing is supported on the bearing device for the clutch. The bearing device is preferably an anti-friction bearing, for example, a deep groove ball bearing or an angular contact ball bearing. However, sliding bearings can also be used, optionally in combination with anti-friction bearings. 
     One preferred exemplary embodiment of the torque transmission device is distinguished by the fact that the bearing device for the clutch is arranged in the axial direction between the actuating bearing and a clutch plate. The bearing device is preferably supported on the free end of the support tube. The support tube also preferably serves to guide the actuating bearing and is therefore of reinforced configuration. 
     A further preferred exemplary embodiment of the torque transmission device is distinguished by the fact that axial projections, such as pins, are provided on or fastened to the clutch cover part, which axial projections extend in the axial direction through an actuating spring device toward a flange part which is fastened to the pins and is supported on the bearing device for the clutch. A plurality of pins which reach through the parts which are arranged between the flange part and the clutch cover part are preferably arranged such that they are distributed uniformly in the circumferential direction. The flange part is preferably supported on an outer bearing ring of the bearing device. An inner ring of the bearing device is preferably supported on the support tube. 
     A further exemplary embodiment of the torque transmission device is distinguished by the fact that the bearing device for the clutch is arranged in the radial direction between the support tube and the flange part. The bearing device is preferably configured in such a way that it absorbs both radial forces and axial forces. 
     A further preferred exemplary embodiment of the torque transmission device is distinguished by the fact that the support tube is fastened to the housing, in particular the transmission housing. At its end on the housing side, the support tube is preferably equipped with a radial flange, which is screwed to the housing. 
     The object, which is specified above, is also achieved in an above-described torque transmission device by virtue of the fact that the bearing device for the clutch is arranged in the radial direction between that end of the support tube which is on the housing side, in particular on the transmission housing side, and a support element which is fixed to the housing, in particular is fixed to the transmission housing. The support element can also be connected integrally to the housing. However, the support element is preferably screwed to the housing. According to one aspect of the invention, the associated screws are accessible through cutouts in parts of the clutch, such as disk springs, a clutch cover, a flange of the support tube and clutch plates. When said cutouts are made to overlap, a tool can be used to reach through the premounted clutch and fasten the support element to the housing by way of the screws. The bearing device is preferably configured as a fixed bearing. Since the fixed bearing, which defines the axial position of the clutch, is preferably arranged close to the actuating bearing or the actuating bearings, the tolerance chain between the actuating system and the clutch is relatively short. As a result, matching of the clutch and the actuating system is made easier. 
     A further preferred exemplary embodiment of the torque transmission device is distinguished by the fact that pins, which extend in the axial direction through an actuating spring device toward a clutch cover part, are fastened to the other end of the support tube. The pins are likewise fastened to the clutch cover part. 
     The object, which is specified above, is also achieved in an above-described torque transmission device by virtue of the fact that the support tube is mounted radially between two shafts, in particular between two transmission input shafts, and is combined with an axial bearing on the engine side. The support tube is preferably not fastened to a clutch cover, but rather to a substantially more rigid central plate of a dual clutch. On account of the small radial installation space between the transmission input shafts, the associated bearing device is preferably configured as a needle bearing. Since no axial forces can be supported via a needle bearing of this type, the axial bearing on the engine side is used, according to one substantial aspect of the invention, in order to relieve an output shaft, in particular a crankshaft, of an internal combustion engine of the axial force of the clutch. The axial bearing on the engine side is configured, for example, as an axial deep groove ball bearing, as a radial deep groove ball bearing or as an angular contact ball bearing. 
     The aim of the present invention is to support the weight, inertia and axial actuating forces which act on the clutch by way of an improved mounting. The torque transmission devices comprise bearing variants for dual clutches, which bearing variants have the following properties, among others: relatively low loading of the crankshaft and the transmission input shafts; the axial forces are not transmitted to the crankshaft or the transmission input shaft; compensation of a slight radial, axial and angular offset between the engine and the transmission; can be implemented with and without a pilot bearing between the crankshaft and the transmission input shaft; and can be combined with many actuating systems, in particular engagement systems, since their installation space is scarcely changed by the improved clutch mounting and, in particular, penetration of the clutch bearing and the actuating system is not required. 
     The bearing concepts according to the invention relate specifically to dual clutches. However, they can also be used for single clutches and hybrid applications. In hybrid applications, the bearing concepts can be used both to mount the unit comprising an electric machine and the clutch, for example a single clutch, a dual clutch or variants with an additional separating clutch, and also to support the clutch between an internal combustion engine and an electric machine or between an electric machine and a transmission. The disclosed baring variants can be combined with clutches which have been pressed closed, pulled closed, pressed open and pulled open. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, features and details of the invention result from the following description, in which various exemplary embodiments are described in detail with reference to the drawings, in which: 
         FIG. 1  shows a torque transmission device according to a first exemplary embodiment, a clutch cover part being mounted on a support tube, in half section; 
         FIG. 2  shows a torque transmission device according to a second exemplary embodiment, a clutch cover part being mounted on a transmission housing via a support tube, in half section; and 
         FIG. 3  shows a torque transmission device according to a third exemplary embodiment, a support tube being mounted between two transmission input shafts and the clutch additionally being mounted by a bearing device on the engine side, in half section. 
     
    
    
       FIGS. 1 to 3  show, in each case, one part of a drive train  1 ;  81 ;  121  of a motor vehicle in half section. A dual clutch  6  is arranged between a drive unit  3 , in particular an internal combustion engine, from which a crankshaft  4  emanates, and a transmission  5 . 
     DETAILED DESCRIPTION OF THE INVENTION 
     In the exemplary embodiment which is shown in  FIG. 1 , a torsional vibration damping device  8  is connected between the drive unit  3  and the dual clutch  6 . The torsional vibration damping device  8  could also be a two mass flywheel. The crankshaft  4  of the internal combustion engine  3  is connected fixedly via screw connections  9  to an input part  11  of the torsional vibration damping device  8 . The input part  11  of the torsional vibration damping device  8  has substantially the design of a circularly annular disk which extends in the radial direction and forms a vibration damper cage radially on the outside. A starter crown gear  12  is fastened to the input part  11  radially on the outside. At least one energy accumulator device, in particular a spring device  16 , is received at least partially in the vibration damper cage. An output part  18  of the torsional vibration damping device  8  engages into the spring device  16 . The output part  18  of the torsional vibration damping device  8  is connected releasably by an intermeshing toothing system  21  to the clutch housing part  22  radially on the inside. An intermediate pressure plate  26  of the dual clutch  6  is fastened to the clutch housing part  22  with the aid of rivet fastenings  24 . On the drive side, friction linings of a first clutch plate  31  can be clamped between the intermediate pressure plate  26  and a pressure plate  28 . The first clutch plate  31  is connected via a hub part  33  in a rotationally fixed manner to a first transmission input shaft  35  which is configured as a solid shaft. The first transmission input shaft  35  is arranged rotatably in a second transmission input shaft  36  which is configured as a hollow shaft. A hub part  43  of a second clutch plate  42  is connected in a rotationally fixed manner to that end of the second transmission input shaft  36  which is on the drive side. Friction linings, which can be clamped between the intermediate pressure plate  26  and a further pressure plate  39 , are fastened to the second clutch plate  42  radially on the outside. 
     The clutch housing part  22  belongs to a clutch housing  44  which, furthermore, comprises a clutch cover part  45 . The clutch cover part  45  is connected fixedly with the aid of the rivet fastening elements  24  to the intermediate pressure plate  26  and the clutch housing part  22 . The clutch housing  44  is connected in a rotationally fixed manner to the crankshaft  4  by the intermeshing toothing system  21 , with the interposition of the torsional vibration damping device  8 . The dual clutch  6  is actuated via actuating devices  46 ,  47  which comprise actuating bearings which in turn interact with actuating levers or actuating lever devices  48 ,  49 . The actuating levers  48 ,  49  are preferably disk springs. The two pressure plates  28 ,  39  can be displaced to a limited extent in the axial direction relative to the intermediate pressure plate  26  by the actuating levers  48 ,  49 . The actuating bearings of the actuating devices  46 ,  47  are actuated by lever devices  51 ,  52 . The associated actuating forces are indicated by arrows  53 ,  54 . 
     The drive trains  1 ,  81 ,  121 , which are shown in half section in  FIGS. 1 to 3 , are similar to one another. The same designations are used to denote identical or similar parts. In order to avoid repetitions, reference is made to the preceding and to the following description of  FIG. 1  in order to describe the same or similar components of  FIGS. 2 and 3 . 
     In the exemplary embodiment shown in  FIG. 1 , a support tube  64  is fastened on a transmission housing  60  of the transmission  5  with the aid of screw connections  61 . At its end on the transmission side, the support tube  64  has a radial flange which bears against the transmission housing  60 . The support tube  64  extends from the radial flange radially to the inside through the actuating devices  46 ,  47  in the axial direction toward the drive unit  3 . In the context of the present invention, the expressions axial direction, radial direction and circumferential direction relate to the rotational axis  62  of the torque transmission devices which are shown in  FIGS. 1 to 3 . 
     A bearing device  66  is supported at that end of the support tube  64  which is on the engine side. The bearing device  66  is also called a support bearing and is configured, for example, as a deep groove ball bearing or as an angular contact ball bearing. The bearing device  66  is arranged in the axial direction between the second clutch plate  42  and the actuating lever  48  which is configured as a disk spring. The bearing device  66  comprises an inner bearing ring which is arranged, for example pushed or pressed, on that end of the support tube  64  which is on the engine side. The inner bearing ring  68  is secured in the axial direction away from the transmission by a securing ring  69  which engages into an annular groove at the free end of the support tube  64 . Furthermore, the bearing device  66  includes an outer bearing ring  70  which is connected to the clutch cover part  45  via a flange part  71  and pins  72 . Radially on the inside, the flange part  71  has a circumferential shoulder which is supported on the outer bearing ring  70 . The flange part  71  is secured in the axial direction away from the transmission  5  by a projection on the outer bearing ring  70 . The pins  72  are fastened radially to the outside of the flange part  71  by way of their ends on the engine side. Those ends of the pins  72  which are on the transmission side are fastened to the clutch cover part  45 . Here, the pins  72  extend through disk spring windows in the actuating lever  48 . 
     The bearing variant, which is shown in  FIG. 1 , can also be implemented for dual clutches with damped clutch plates. When the dual clutch  6  is fastened to the crankshaft  4  by way of a rotationally fixed connection instead of by way of an external damper  8 , a radial, axial or angular offset which possibly occurs between the engine and the transmission can be compensated for elastically, for example, by a cardanic connection. 
     During the mounting of the torque transmission device, which is shown in  FIG. 1 , first of all the actuating system is fastened to the transmission housing  60 . The dual clutch  6 , which is preferably equipped with separable clutch plates  31 ,  42 , is then mounted on the actuating system. Here, the inner bearing ring  68  of the support bearing  66  is pushed onto the bearing seat of the support tube  64  and is subsequently secured with the aid of the securing ring  69 , which is preferably configured as a shaft securing ring. According to a further aspect of the invention, the support tube  64  also serves to guide the actuating device  46 ,  47 . The support tube  64  is therefore also called a guide tube. After the inner bearing ring  68  is pushed onto the support tube  64 , the hubs  33 ,  43  of the clutch plates  31 ,  42  can be inserted and fixed. The input part  11  of the external torsional vibration damper  8  is screwed to the crankshaft  4 . When the engine  4  and the transmission  5  are joined together, the torsional vibration damping device  8  is connected to the dual clutch  6  by the intermeshing toothing system  21 . 
     As an alternative, the clutch and the actuating system can also be mounted as a module in a clutch housing. However, this presupposes that the fastening elements of the actuating system are not covered by the clutch. This can be avoided, for example, by cutouts in the clutch. When the clutch and the actuating system are mounted as a unit, separable clutch plates are not required. 
     In the exemplary embodiment, which is shown in  FIG. 2 , the fixed bearing/floating bearing principle is applied for mounting the dual clutch  6 . A drive plate  84 , which is also called a flexiplate, is used as floating bearing. The flexiplate produces a rotationally fixed connection between the crankshaft  4  and a clutch housing part  86 . However, a flexible design of the flexiplate makes a movement of the clutch housing part  86  possible, in particular in the axial direction, relative to the crankshaft  4 . The starter crown gear  12  is fastened to the flexiplate  84  radially on the outside. The clutch housing part  86  is connected integrally to the intermediate pressure plate  26 . The clutch cover part  45  is fastened to the clutch housing part  86  by the rivet fastening elements or screw connection elements  24 . 
     A support element  92 , which is of substantially annular configuration and has an angular cross section, is fastened on the transmission housing  60  with the aid of screw connections  91 . An outer bearing ring  93  of a bearing device  95  is supported on the support element  92  radially on the inside. The bearing device  95  represents the fixed bearing which can absorb axial and radial forces. The fixed bearing  95  is preferably configured as an antifriction bearing, for example, as a deep groove ball bearing or angular contact ball bearing. The bearing device  95  comprises an inner bearing ring  96  which is pushed onto that end of a support tube  98  which is on the transmission side. The inner bearing ring  96  is secured by a securing ring  94  in the axial direction toward the transmission  5 . 
     The support tube  98  comprises an axial section  97  which extends from the transmission  5  toward the engine  3 . At its end on the engine side, the support tube  98  comprises a fastening section  99  which extends in the radial direction. Pins  100  are fastened to the fastening section  99  radially on the outside. The pins  100  extend through corresponding disk spring windows in the actuating lever  48  which is configured as a disk spring. Those ends of the pins  100  which are on the transmission side are fastened to the clutch cover part  45 . 
     According to a further aspect of the invention, the support tube  98 , which rotates with the clutch cover part  45 , also serves to guide the actuating devices  46 ,  47  and is therefore also called a guide tube. Since the fixed bearing  95 , which defines the axial position of the dual clutch  6 , is arranged close to the actuating system  46 ,  47 , the tolerance chain between the actuating system and the dual clutch can be kept short. As a result, matching of the clutch and the actuating system is made easier. A radial offset between the engine  4  and the transmission  5  can be compensated for by tilting of the dual clutch  6 . The tilting angle can be kept small by the support tube  98  which is fixed to the cover and at the transmission side end of which the locating bearing  95  is arranged. 
     The torque transmission device shown in  FIG. 2  includes rigid clutch plates  31 ,  42 . However, the bearing concept which is shown in  FIG. 2  can also be combined with damped clutch plates, jolt compensating plates or a two mass flywheel. The mounting of the torque transmission device which is shown in  FIG. 2  functions as follows. 
     When the actuating system and the dual clutch are mounted in the clutch housing, axial securing of the locating bearing  95  is scarcely possible, on account of the restricted accessibility. Therefore, in the bearing variant which is shown in  FIG. 2 , the dual clutch  6  and the actuating system  46 ,  47  are first premounted. The premounted module is subsequently mounted. In order for it to be possible to fix the actuating system on the transmission housing  60 , the screws  91  have to be accessible. According to a further aspect of the invention, this is made possible by cutouts in the disk springs  48 ,  49 , the clutch cover part  45 , the flange  99  of the support tube  98  and the clutch plates  31 ,  42 . When said cutouts are made to overlap, a tool can be used to reach through the dual clutch  6  and screw the actuating system to the transmission housing  60 , in particular a transmission housing wall. The flexiplate  84  is fastened to the crankshaft  4  with the aid of the screws  9 . After the engine  4  and the transmission  5  are joined together, the flexiplate  84  is screwed to the clutch housing part  86  by screw connection elements  104 . 
     If the clutch and the actuating system cannot be mounted as a unit in the clutch housing, the bearing variant, which is shown in  FIG. 2 , can be mounted in a similar manner as in the exemplary embodiment which is shown in  FIG. 1  as a result of separable clutch plates and a connecting point between the support tube  98  and the fastening section  99  which is also called a flange. 
     The exemplary embodiment, which is shown in  FIG. 3  is similar to the preceding exemplary embodiment, which is shown in  FIG. 2 . The main difference between these two exemplary embodiments lies in the fact that the support tube  145  is not fastened to the clutch cover  45 , but rather to the intermediate plate  26  which is also called a central plate. A further difference is that in each case one torsional vibration damper  122 ,  124  is integrated into the clutch plates  31 ,  42 . Moreover, a driver plate  126  is provided in addition to the flexiplate  84 . The driver plate  126  includes a radial section  127  and an axial section  128 . The axial section  128  is fastened to the intermediate plate  26  or the central plate  26  radially on the outside with the aid of screw connections  131 . 
     The flexiplate  84  is fastened to the radial section  127  of the driver plate  126  radially on the outside with the aid of rivet fastening elements  132 . Radially on the inside, the radial section  127  has a support ring  134  which is supported on an outer bearing ring  136  of a bearing device  135 . The bearing device  135  has an inner bearing ring  138  which bears against an engine housing  140  by way of its end side on the engine side. A certain play is provided in the radial direction between the inner bearing ring  138  and the engine housing  140 . An axial bearing, for example an axial deep groove ball bearing, a radial deep groove ball bearing or an angular contact ball bearing, represents the bearing device  135  and serves to relieve the crankshaft  4  of the axial force of the clutch  6 . The dual clutch  6  is supported on the engine housing  140  by the axial bearing  135 . 
     The support tube  145  extends in the axial direction in an annular space between the two transmission input shafts  35 ,  36 . The support tube  145  comprises an axial section  146  and a radial section  148 . The radial section  148  is fastened to the intermediate plate  26  with the aid of rivet fastening elements  149 . The axial section  146  is mounted with its free end on the transmission input shaft  36  with the aid of a bearing device  150 . The bearing device  150  is preferably configured as a needle bearing. 
     The mounting of the torque transmission device, which is shown in  FIG. 3 , functions as follows: after the actuating system has been mounted in the clutch housing, the dual clutch  6  is pushed onto the transmission input shafts  35 ,  36 . If an axial bearing on the transmission side is provided, it has to be supported on the actuating system or on a transmission wall and possibly has to be secured axially. If an axial bearing  135  on the engine side is provided, as in the example which is shown, the flexiplate  84  and the driver plate  126 , which represents a connecting element between the intermediate plate  26  and the flexiplate  84 , are fastened together with the axial bearing  135  on the engine side to the engine housing  140 . After the mounting of the engine  4  and the transmission  5 , the driver plate  126  is screwed to the central plate  26  by the screw connection elements  131 . For this purpose, at least one opening has to be provided in the clutch housing. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 List of Designations 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1. 
                 Drive train 
               
               
                 3. 
                 Drive unit 
               
               
                 4. 
                 Crankshaft 
               
               
                 5. 
                 Transmission 
               
               
                 6. 
                 Dual clutch 
               
               
                 8. 
                 Torsional vibration damping 
               
               
                   
                 device 
               
               
                 9. 
                 Screw connection 
               
               
                 11. 
                 Input part 
               
               
                 12. 
                 Starter crown gear 
               
               
                 16. 
                 Spring device 
               
               
                 18. 
                 Output part 
               
               
                 21. 
                 Intermeshing toothing system 
               
               
                 22. 
                 Clutch housing part 
               
               
                 24. 
                 Rivet fastenings 
               
               
                 26. 
                 Intermediate pressure plate 
               
               
                 28. 
                 Pressure plate 
               
               
                 31. 
                 First clutch plate 
               
               
                 33. 
                 Hub part 
               
               
                 35. 
                 First transmission input shaft 
               
               
                 36. 
                 Second transmission input shaft 
               
               
                 39. 
                 Pressure plate 
               
               
                 42. 
                 Second clutch plate 
               
               
                 43. 
                 Hub part 
               
               
                 44. 
                 Clutch housing 
               
               
                 45. 
                 Clutch cover part 
               
               
                 46. 
                 Actuating device 
               
               
                 47. 
                 Actuating device 
               
               
                 48. 
                 Actuating lever 
               
               
                 49. 
                 Actuating lever 
               
               
                 51. 
                 Lever device 
               
               
                 52. 
                 Lever device 
               
               
                 53. 
                 Arrow 
               
               
                 54. 
                 Arrow 
               
               
                 60. 
                 Transmission housing 
               
               
                 61. 
                 Screw connection 
               
               
                 62. 
                 Rotational axis 
               
               
                 64. 
                 Support tube 
               
               
                 66. 
                 Bearing device 
               
               
                 68. 
                 Inner bearing ring 
               
               
                 69. 
                 Securing ring 
               
               
                 70. 
                 Outer bearing ring 
               
               
                 71. 
                 Flange part 
               
               
                 72. 
                 Pin 
               
               
                 81. 
                 Drive train 
               
               
                 84. 
                 Drive plate 
               
               
                 86. 
                 Clutch part 
               
               
                 91. 
                 Screw connection 
               
               
                 92. 
                 Support element 
               
               
                 93. 
                 Outer bearing ring 
               
               
                 94. 
                 Safety bolt 
               
               
                 95. 
                 Bearing device 
               
               
                 96. 
                 Inner bearing ring 
               
               
                 97. 
                 Axial section 
               
               
                 98. 
                 Support tube 
               
               
                 99. 
                 Actuating section 
               
               
                 100. 
                 Pin 
               
               
                 104. 
                 Screw connection element 
               
               
                 121. 
                 Drive train 
               
               
                 122. 
                 Torsional vibration damper 
               
               
                 124. 
                 Torsional vibration damper 
               
               
                 126. 
                 Driver plate 
               
               
                 127. 
                 Radial section 
               
               
                 128. 
                 Axial section 
               
               
                 131. 
                 Screw connection 
               
               
                 132. 
                 Rivet fastening element 
               
               
                 134. 
                 Support ring 
               
               
                 135. 
                 Bearing device 
               
               
                 136. 
                 Outer bearing ring 
               
               
                 138. 
                 Inner bearing ring 
               
               
                 140. 
                 Engine housing 
               
               
                 145. 
                 Support tube 
               
               
                 146. 
                 Axial section 
               
               
                 148. 
                 Radial section 
               
               
                 149. 
                 Rivet fastening element 
               
               
                 150. 
                 Transmission input shaft