Abstract:
A clutch disc for a disengaging torque transmission device includes a carrier plate on which a friction lining is provided for non-positive closure of the torque transmission device. At least one vibration-influencing area is formed on the carrier plate for influencing the vibration behaviour of the clutch disc, in particular for damping at least one defined clutch disc vibration, the vibration-influencing area being formed by an opening and/or by an impression on the carrier plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority of DE 10 2015 014 396.4, filed Nov. 6, 2015, which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a clutch disc for a disengaging torque transmission device, a disengaging torque transmission device having the clutch disc and a vehicle, in particular a commercial vehicle, having the disengaging torque transmission device. 
         [0003]    A disengaging torque transmission device or a releasable clutch, which serves for connecting a drive unit of the vehicle, for example an internal combustion engine or an electrical machine, to a transmission of the vehicle for the transmission of torque, is routinely provided on a vehicle. Here the releasable clutch comprises a shifting clutch disc connected to a transmission input shaft for the transmission of torque, which is pressed against a flywheel of the internal combustion engine, for example, in order to close the clutch. In this way a non-positive or frictional connection is established between the internal combustion engine and the transmission. The clutch disc usually comprises a carrier plate, which is provided with a friction lining at least on a side facing the internal combustion engine flywheel. 
         [0004]    During closing of the clutch, in particular, and also in the closed state of the clutch, the carrier plate of the clutch disc is prone to vibrate, often heavily. These vibrations are generated, for example, by the torque-transmitting connection of the transmission input shaft to the clutch disc. Furthermore, the carrier plate may also be led to vibrate by the frictional heat input into the carrier plate. The heat input into the carrier plate may cause such a deformation or expansion of the carrier plate that the carrier plate buckles. As a result of this buckling of the carrier plate, the clutch disc comes to bear only on areas of the internal combustion engine flywheel, so that it likewise begins to vibrate, owing to the relative movement between the clutch disc and the internal combustion engine flywheel. The vibrations of the carrier plate often cause distinctly audible noises, particularly in natural frequency ranges of the carrier plate. The vibrations of the carrier plate moreover have a negative effect on the durability of the clutch disc, especially on the durability of the friction lining of the clutch disc. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    An object of the invention, therefore, is to provide a clutch disc for a disengaging torque transmission device, which has an improved vibration behaviour. 
         [0006]    In one embodiment, a clutch disc for a disengaging torque transmission device includes a carrier plate, on which a friction lining is provided for non-positive closure of the torque transmission device. According to this embodiment at least one vibration-influencing area is formed on the carrier plate for influencing the vibration behaviour of the clutch disc, in particular for damping at least one defined clutch disc vibration, the vibration-influencing area being formed by an opening and/or by an impression or depression on the carrier plate. 
         [0007]    Vibration behaviour of the clutch disc is significantly improved because at least the one opening and/or at least the one impression specifically interrupt or damp vibrations of the carrier plate, so that the vibrations cannot spread to the usual degree. Furthermore, at least the one opening and/or at least the one impression also serve specifically to counteract a thermally induced buckling of the carrier plate and therefore a thermally induced generation of vibrations in the carrier plate. 
         [0008]    Here the shape and position of at least the one vibration-influencing area and the number of vibration-influencing areas may depend, for example, on the type of vibration to be influenced, the frequency of the vibration to be influenced, the thickness of the carrier plate, the carrier plate material or the direction of rotation of the carrier plate. 
         [0009]    The term “impression” is here expressly to be interpreted in a wide sense. Thus the impression may be formed, for example, by impressing or deforming just one main face wall of the carrier plate. The impression may equally well be formed by pressing the carrier plate through, so that both main face walls of the carrier plate are deformed. 
         [0010]    In a preferred embodiment of the clutch disc at least the one opening extends continuously or right through the carrier plate in the carrier plate thickness direction. This is an especially effective way of interrupting or damping the vibrations of the carrier plate. The through-opening here can be produced, for example, by a laser, by a milling cutter, a stamping machine or by erosion. Alternatively, however, at least the one opening may also naturally not extend right through the carrier plate, so that the opening extends through the carrier plate to a depth which is less than the thickness of the carrier plate. 
         [0011]    In a top view of the carrier plate, at least the one vibration-influencing area preferably runs linearly, i.e., along a line, in particular in a curved path, in order to allow effective influencing of the vibrations of the carrier plate and at the same time to afford the carrier plate a high degree of strength. It is preferred here that a first end area of the linear vibration-influencing area be arranged radially inside a second end area of the vibration-influencing area, in order to effectively counteract a thermally induced buckling of the carrier plate. It is furthermore preferable for at least an end area of the vibration-influencing area to be arranged after an area of the vibration-influencing area immediately adjoining the end area, viewed in the direction of rotation of the clutch disc. 
         [0012]    In a preferred development at least the one vibration-influencing area runs rectilinearly instead of along a curved path. Here at least the one rectilinear vibration-influencing area preferably runs in the clutch disc radial direction, in order to counteract a thermally induced buckling of the carrier plate. It is furthermore preferred that at least the one rectilinear vibration-influencing area be separated by a defined interval from a radially inner wall of the carrier plate. It is equally preferable for at least the one rectilinear vibration-influencing area to be separated by a defined interval from a radially outer wall of the carrier plate. 
         [0013]    As an alternative to the rectilinear course of the vibration-influencing area, at least the one linear vibration-influencing area may also be of a meandering form. It is preferable here for at least the one meandering vibration-influencing area to be of a substantially sinusoidal form with an amplitude diminishing inwards in the clutch disc radial direction. Such a development of the vibration-influencing area likewise serves effectively to counteract a thermally induced buckling of the carrier plate. 
         [0014]    It is furthermore preferred that at least the one meandering vibration-influencing area be separated by a defined interval from a radially inner wall of the carrier plate. It is equally preferable for at least the one meandering vibration-influencing area to be separated by a defined interval from a radially outer wall of the carrier plate. 
         [0015]    As a further alternative to the rectilinear course of the vibration-influencing area at least the one linear vibration-influencing area may also be of a substantially hook-shaped form. It is preferred here that at least the one hook-shaped vibration-influencing area open with an end area into a radially outer wall of the carrier plate. 
         [0016]    The hook-shaped vibration-influencing area proceeding from the radially outer wall of the carrier plate furthermore preferably comprises a substantially S-shaped portion, adjoining which is a substantially C-shaped portion of the hook-shaped vibration-influencing area. It is especially preferred if the hook-shaped vibration-influencing area here is formed according to the embodiment of the hook-shaped vibration-influencing area shown in  FIG. 6 . Alternatively and/or in addition, the hook-shaped vibration-influencing area, also proceeding from the radially outer wall of the carrier plate, may also be of a substantially L-shaped or a substantially U-shaped form with a shortened U-leg. 
         [0017]    In a preferred embodiment the impression, viewed in cross section transversely to the course of the vibration-influencing area, is of meandering and/or undulating form, in order to be able to interrupt or damp the vibrations of the carrier plate in an especially effective manner. 
         [0018]    In order to reduce the notch effect of the linear vibration-influencing area, at least an end area of the vibration-influencing area, in a top view of the carrier plate, is expanded and/or wider or laterally extended compared to an adjoining area of main extent of the vibration-influencing area. This is an effective way of counteracting high notch stresses on the end area of the vibration-influencing area. 
         [0019]    Alternatively and/or in addition, in order to reduce the notch effect of the vibration-influencing area at least an end area of the vibration-influencing area may have a round, in particular drop-shaped and/or a circular and/or a spherical external contour. 
         [0020]    In an embodiment of the invention, the clutch friction lining is formed by at least one friction plate fixed to the carrier plate, the friction plate being assigned to a main face wall of the carrier plate, at least the one impression of the carrier plate protruding from this main face wall in the carrier plate thickness direction, and the friction plate having at least one opening, into which at least the one impression protruding from the main face wall of the carrier plate extends. This affords an especially simple clutch disc construction. Here the friction plate may be riveted or screwed to the carrier plate, or adhesively bonded onto the carrier plate. If a substantially laminar spring element is arranged between the carrier plate and the friction plate, at least one opening is likewise preferably provided on the spring element, through which at least the one protruding impression extends. 
         [0021]    At least the one opening preferably extends continuously or right through the friction plate in the friction plate thickness direction, as an especially effective way of interrupting or damping the vibrations of the carrier plate. Alternatively, however, at least the one opening may extend through the friction plate only to a depth which is less than the thickness of the friction plate. 
         [0022]    In a further preferred embodiment multiple vibration-influencing areas are formed on the carrier plate. In this case the multiple vibration-influencing areas are preferably arranged at an interval from one another and/or uniformly distributed over the carrier plate, viewed in a clutch disc circumferential direction, as an effective way of influencing the vibrations of the carrier plate. 
         [0023]    At least a number of the multiple vibration-influencing areas, in a top view of the carrier plate, have a different course from at least another number of the multiple vibration-influencing areas. Here multiple, in particular three, groups are preferably provided, each having multiple, in particular four, vibration-influencing areas, the vibration-influencing areas of the respective group having an identical linear course and the groups being distinguished from one another by the course of the vibration-influencing areas. 
         [0024]    In a preferred embodiment, the clutch friction lining is formed by multiple, in particular two, friction plates fixed to the carrier plate, at least one friction plate being assigned to a first main face wall of the carrier plate, and at least one friction plate being assigned to a second main face wall of the carrier plate. Here a disc-shaped friction plate, for example, may be assigned to the respective main face wall of the carrier plate. Alternatively, multiple thinner or thicker sector-shaped friction plates, which are distributed in the clutch disc circumferential direction, may also be assigned to the respective main face wall of the carrier plate. 
         [0025]    At least one substantially disc-shaped spring element, which serves to cushion axial forces acting on the clutch disc, is furthermore preferably arranged between at least one main face wall of the carrier plate and the assigned friction plate. 
         [0026]    In addition, a disengaging torque transmission device or a releasable clutch comprising the clutch disc according to the invention is also claimed. The advantages accruing from this are identical to the advantages of the clutch disc according to the invention already assessed, so these will not be repeated at this juncture. 
         [0027]    Furthermore, a vehicle, in particular a commercial vehicle, having the disengaging torque transmission device according to the invention is also claimed. The advantages accruing from this are likewise identical to the advantages of the clutch disc according to the invention already assessed, so these will likewise not be repeated at this juncture. 
         [0028]    In a preferred development of the vehicle the clutch disc is at the same time connected to an input shaft of a vehicle transmission for the transmission of torque. 
         [0029]    Except in instances of clear dependencies or irreconcilable alternatives, for example, the advantageous embodiments and developments of the invention explained above and/or described in the dependent claims may be used individually or also in any combination with one another. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The invention and its advantageous embodiments and developments together with their advantages are explained in more detail below merely by way of example, referring to drawings, of which: 
           [0031]      FIG. 1  is a side view of a truck having the disengaging torque transmission device according to the invention; 
           [0032]      FIG. 2  is a sectional view through the disengaging torque transmission device according to an embodiment of the invention; 
           [0033]      FIG. 3  is a top view of a clutch disc of the transmission device according to an embodiment of the invention; 
           [0034]      FIG. 4  is a sectional representation along the plane of section A-A in  FIG. 3 ; 
           [0035]      FIG. 5  is a top view of a second embodiment of the clutch disc; 
           [0036]      FIG. 6  is a top view of a third embodiment of the clutch disc; 
           [0037]      FIG. 7  is a top view of a fourth embodiment of the clutch disc; 
           [0038]      FIG. 8  is a sectional view through a fifth embodiment of the clutch disc; and 
           [0039]      FIG. 9  is a sectional view of a sixth embodiment of the clutch disc. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0040]      FIG. 1  shows a vehicle  1 , here embodied as a truck, for example. The vehicle  1  comprises a first embodiment of a disengaging torque transmission device  3  or a releasable clutch, indicated in  FIG. 1  by dashed lines, which serves for connecting an internal combustion engine, forming a drive unit of the vehicle  1 , to a transmission of the vehicle  1  for the transmission of torque. The construction of the torque transmission device  3  is explained in more detail below with reference to  FIG. 2 : 
         [0041]    According to the section through the torque transmission device  3  shown in  FIG. 2 , the torque transmission device  3  here, for example, comprises a flywheel  5  on the internal combustion engine side, a clutch disc  8  connected to a transmission input shaft  7  for the transmission of torque, with a friction lining  9 , a pressure plate  11 , a clutch spring or a diaphragm spring  13 , a clutch operator  15  and a clutch release lever  17 . Furthermore, the clutch disc  8  here, for example, is connected via a torsional-vibration damper  19  to the transmission input shaft  7 . In  FIG. 2  the torque transmission device  3  is shown in a closed state, so that the flywheel  5  on the internal combustion engine side and the input shaft  7  on the transmission side are connected to one another via a power flow  21  for the transmission of torque. In addition, the construction shown in  FIG. 2  is only one example of the configuration of the torque transmission device  3 , which is intended to demonstrate the basic construction and the fundamental working of the torque transmission device  3 . The torque transmission device  3  according to the invention, however, is expressly not limited to such a construction. For example, the torsional-vibration damper  19  need not necessarily be provided on the torque transmission device  3 . 
         [0042]      FIG. 3  shows a view from above or top view of the clutch disc  8 . The friction lining  9  here is indicated by dashed lines, so that the carrier plate  10  of the clutch disc  8  is visible. The carrier plate  10  here, for example, comprises multiple vibration-influencing areas  23 , which serve to influence the vibration behaviour of the clutch disc. In concrete terms, the carrier plate  10  here, for example, comprises four substantially linear vibration-influencing areas  23 , which have an identical course and are arranged over the carrier plate  10 , separated by uniform intervals from one another, here by 90°, for example, and in the clutch disc circumferential direction u. Each linear vibration-influencing area  23  here, for example, is of substantially sinusoidal form with an amplitude diminishing inwards in the clutch disc radial direction r ( FIG. 4 ). Moreover, each vibration-influencing area  23  here, for example, is separated by a defined interval from the radially inner wall  25  of the carrier plate  10 . Furthermore, each vibration-influencing area  23  here, for example, is also separated by a defined interval from a radially outer wall  27  of the carrier plate  10 . 
         [0043]    According to  FIG. 3 , moreover, end areas  29  of the respective sinusoidal vibration-influencing area  23 , in a top view of the carrier plate  10 , are here expanded or of wider formation compared an adjoining area of extent  31  of the sinusoidal vibration-influencing area  23 . In concrete terms each end area  29  of the respective vibration-influencing area  23  here has a drop-shaped external contour, for example. This reduces the notch effect of the linear vibration-influencing areas  23 . In addition, each end area  29  of the linear vibration-influencing areas  23  here is moreover arranged after an area  30  of the respective linear vibration-influencing area  23  immediately adjoining the respective end area  29 , viewed in the direction of rotation D of the clutch disc  8 . 
         [0044]      FIG. 4  shows a section through the clutch disc  8  along the plane of section A-A in  FIG. 3 . It is apparent from this representation that here each linear vibration-influencing area  23  is formed by an opening  33  provided on the carrier plate  10 , which extends continuously or right through the carrier plate  10  in the carrier plate thickness direction or in clutch disc thickness direction d. 
         [0045]    In addition, the friction lining  9  of the clutch disc  8  here, for example, is formed by two friction plates  35 ,  36  fixed to the carrier plate  10 . Here the friction plate  35  is in flat contact with a first main face wall  37  of the carrier plate  10 . The friction plate  36  is in flat contact with a second main face wall  39  of the carrier plate  10  opposite the first main face wall  37 . The friction plates  35 ,  36  may be fixed to the carrier plate  10  by means of riveted connection, a screwed connection or also by means of an adhesively bonded connection, for example. 
         [0046]      FIG. 5  shows a second embodiment of the clutch disc  8 . Compared to the first embodiment of the clutch disc  8  shown in  FIG. 3 , the carrier plate  10  of the clutch disc  8  here does not have any sinusoidal vibration-influencing areas  23 , but vibration-influencing areas  41  running rectilinearly in the clutch disc radial direction r. Each rectilinear vibration-influencing area  41  here, for example, is likewise separated by a defined interval from the radially inner wall  25  and by a defined interval from the radially outer wall  27  of the carrier plate  10 . Furthermore, in a top view of the carrier plate  10 , end areas  43  of the respective rectilinear vibration-influencing area  41  are here likewise expanded or of wider formation compared to an adjoining area of main extent  45  of the respective vibration-influencing area  41 . Furthermore, the end areas  43  of the rectilinear vibration-influencing areas  41  here also have a drop-shaped external contour. 
         [0047]      FIG. 6  shows a third embodiment of the clutch disc  8 . Compared to the first embodiment of the clutch disc  8  shown in  FIG. 3 , no sinusoidal vibration-influencing areas  23  are provided here, but instead vibration-influencing areas  47  of a substantially hook-shaped form. An end area  49  of the respective vibration-influencing area  47  here at the same time opens into the radially outer wall  27  of the carrier plate  10 , so that the radially outer wall  27  of the carrier plate  10  is interrupted at this point. Proceeding from the radial outer wall  27  of the carrier plate  10 , each hook-shaped vibration-influencing area  47  here, for example, comprises a substantially S-shaped portion  51 , adjoining which is a substantially C-shaped portion  53  of the respective hook-shaped vibration-influencing area  47 . Here, in a top view of the carrier plate  10 , an end area  55  of the respective vibration-influencing area  47  is expanded or of wider formation compared to an area of main extent  57  of the respective hook-shaped vibration-influencing area  47 , and has a drop-shaped external contour. 
         [0048]      FIG. 7  shows a fourth embodiment of the clutch disc  8 . Compared to the first embodiment of the clutch disc  8  shown in  FIG. 3 , the carrier plate here comprises not only the sinusoidal vibration-influencing areas  23 , but also the rectilinear vibration-influencing areas  41  and the hook-shaped vibration-influencing areas  47 . Consequently, the carrier plate  10  here, for example, comprises three groups each of four linear vibration-influencing areas  23 ,  41 ,  47 . The four linear vibration-influencing areas  23 ,  41 ,  47  in a group here have an identical linear course. The three groups are moreover distinguished from one another by the linear course of their vibration-influencing areas  23 ,  41 ,  47 . In addition, the vibration-influencing areas  23 ,  41 ,  47  here are likewise separated by an interval from one another and, viewed in the clutch disc circumferential direction u, are distributed uniformly over the carrier plate  10 . 
         [0049]      FIG. 8  shows part of a fifth embodiment of the clutch disc  8 . Compared to the first embodiment of the clutch disc  8  shown in  FIG. 4 , each vibration-influencing area  23  here is not formed by an opening  33 , but by an impression  59  on the carrier plate  10  of the clutch disc  8 . Viewed in cross section transversely to the linear course of the respective vibration-influencing area  23 , each impression  59  here, for example, is of meandering or undulating shape. Moreover, each impression  59  here, for example, projects from the main face wall  37  of the carrier plate  10  in the carrier plate thickness direction or in the clutch disc thickness direction d, in the direction of the friction plate  35  bearing on the main face wall  37 . In the area of the respective impression  59 , the friction plate  35  bearing on the main face wall  37  here, for example, in each case comprises an opening  61 , into which the impression  59  projecting from the main face wall  37  of the carrier plate  10  extends. The opening  61  here, for example, extends through the friction plate  35  bearing on the main face wall  37  to a depth which is less than the friction plate thickness, so that a main face wall  63  of the friction plate  35  remote from the main face wall  37  is not interrupted here. 
         [0050]      FIG. 9  shows a sixth embodiment of the clutch disc  8 . Compared to the embodiment shown in  FIG. 8 , the respective opening  62  here extends continuously or right through the friction plate  35  bearing on the main face wall  37  in the clutch disc thickness direction d, so that the main face wall  63  of the friction plate  35  is interrupted here. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           1  vehicle 
           3  torque transmission device 
           5  flywheel 
           7  input shaft 
           8  clutch disc 
           9  friction lining 
           10  carrier plate 
           11  pressure plate 
           13  diaphragm spring 
           15  clutch operator 
           17  clutch release lever 
           19  torsional-vibration damper 
           21  power flow 
           23  vibration-influencing area 
           25  radially inner wall 
           27  radially outer wall 
           29  end area 
           30  area 
           31  area of main extent 
           33  opening 
           35  friction plate 
           36  friction plate 
           37  main face wall 
           39  main face wall 
           41  vibration-influencing area 
           43  end area 
           45  area of main extent 
           47  vibration-influencing area 
           49  end area 
           51  portion 
           53  portion 
           55  end area 
           57  area of main extent 
           59  impression 
           61  opening 
           62  opening 
           63  main face wall 
         d clutch disc thickness direction 
         D clutch disc direction of rotation 
         r clutch disc radial direction 
         u clutch disc circumferential direction