Patent Abstract:
The invention relates to a centrifugal-force pendulum having a pair of pendulum masses and a pendulum flange, in which a curved cut-out having a cut-out contour is provided, wherein the pendulum masses of the pair of pendulum masses are arranged on both sides of the pendulum flange and are connected to each other by at least one spacer pin led through the cut-out, wherein the spacer pin has a damping arrangement which comprises at least one stabilizing element and at least one elastic damping element ( 64 ), wherein the damping arrangement is designed to damp an impact of the spacer pin on the cut-out contour of the cut-out, wherein end compression of the damping element can be carried out by the impact, wherein the stabilizing element limits the end compression.

Full Description:
[0001]    The present invention relates to a centrifugal pendulum. 
       BACKGROUND 
       [0002]    A centrifugal pendulum is known from DE 10 2011 013 232 A1, which includes a pendulum flange and pendulum masses fastened on both sides of the pendulum flange with the aid of a spacer bolt accommodated in an arc-shaped cutout of the pendulum flange, a movement of the pendulum mass pair being limited by a stop. The spacer bolt has a damping system, which includes a damping element and a ring surrounding the damping element. The ring is designed to strike a cutout contour of the cutout. 
       SUMMARY OF THE INVENTION 
       [0003]    It is an object of the present invention to increase the reliability of the centrifugal pendulum while simultaneously reducing noise emissions. 
         [0004]    The present invention provides a centrifugal pendulum, which includes a pendulum mass pair and a pendulum flange, in which an arc-shaped cutout having a cutout contour is provided, the pendulum masses of the pendulum mass pair being situated on both sides of the pendulum flange and being connected to each other with the aid of at least one spacer bolt guided through the cutout, and the spacer bolt having a damping system, which includes at least one stabilizing element and at least one elastic damping element, and the damping system being designed to damp an impact of the spacer bolt on the cutout contour of the cutout, a compression of the damping element being able to occur, due to the impact. The stabilizing element limits the compression. 
         [0005]    In another special specific embodiment of the present invention, the spacer bolt includes a spacer bolt body, the damping element being situated on a circumferential surface of the spacer bolt body, and the stabilizing element being situated on a front surface of the damping element. 
         [0006]    A stabilizing element is preferably provided on each front surface of the damping element, so that the damping element is axially limited by the stabilizing element. Each front surface of the damping element may also be surrounded at least in sections by a shared stabilizing element, so that the damping element is axially limited by the stabilizing element. 
         [0007]    In another special specific embodiment of the present invention, at least one damping element has an essentially rectangular cross section. 
         [0008]    In another special specific embodiment of the present invention, at least one damping element has an essentially L-shaped cross section. 
         [0009]    In another special specific embodiment of the present invention, at least one damping element has an essentially U-shaped cross section. 
         [0010]    In another special specific embodiment of the present invention, at least one stabilizing element has a smaller outer diameter than the damping element. 
         [0011]    In another special specific embodiment of the present invention, at least one stabilizing element surrounds an outer circumference and/or an inner circumference of the damping element at least in sections. 
         [0012]    In another special specific embodiment of the present invention, at least one stabilizing element has a solidity which is greater than the solidity of the damping element. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The present invention is explained in greater detail below with reference to the figures. The same components are identified by the same reference numerals. Specifically: 
           [0014]      FIG. 1  shows a side view of a torsional vibration damper, including a centrifugal pendulum situated thereon; 
           [0015]      FIG. 2  shows a perspective view of the centrifugal pendulum; 
           [0016]      FIG. 3  shows a perspective view of a cutout of the centrifugal pendulum illustrated in  FIG. 2 ; 
           [0017]      FIG. 4  shows a special specific embodiment of a spacer bolt of the centrifugal pendulum illustrated in  FIGS. 1 through 3 ; 
           [0018]      FIG. 5  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention; 
           [0019]      FIG. 6  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention; 
           [0020]      FIG. 7  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention; 
           [0021]      FIG. 8  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention; 
           [0022]      FIG. 9  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention; 
           [0023]      FIG. 10  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention; 
           [0024]      FIG. 11  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention; 
           [0025]      FIG. 12  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention; and 
           [0026]      FIG. 13  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt in another special specific embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]      FIG. 1  shows a side view of a torsional vibration damper  10 , including a centrifugal pendulum  12  situated thereon; A disk carrier  16 , functioning as a clutch output of a clutch device, is situated on a damper input part  14  of a torsional vibration damper  10  designed as a series damper. The clutch device may be designed, for example, as a converter lockup clutch or as a wet clutch. Torsional vibration damper  10  is actively connected between the clutch output and an output hub  18 , output hub  18  being connectable to a transmission input shaft of a transmission in a drive train of a motor vehicle via a toothing  20 . 
         [0028]    Damper input part  14  is accommodated, centered radially on the inside of output hub  18  and axially secured, and encompasses first energy storage elements  22  radially on the outside, for example bow springs, which actively connect damper input part  14  to a damper intermediate part  24 , damper intermediate part  24  being restrictively rotatable with respect to damper input part  14 . Damper intermediate part  24 , in turn, is restrictively rotatable with respect to a damper output part  28  via the action of second energy storage elements  26  situated radially farther to the inside, for example pressure springs. Damper output part  28  is rotatably fixedly connected to output hub  18 , for example via a welded connection. 
         [0029]    Damper intermediate part  24  includes two disk parts  30 ,  32 , which are spaced an axial distance apart and axially surround damper output part  28 . The one disk part  32  is elongated radially outwardly to form a pendulum flange  34 . Pendulum flange  34  is integrated into disk part  32 , but may also be fastened thereto as a separate component. Pendulum flange  34  is part of centrifugal pendulum  12 . Disk part  32  is rotatably fixedly connected radially on the inside to a turbine hub  36 , which is designed to connect a turbine wheel of a hydrodynamic torque converter. Turbine hub  36  is centered on output hub  18  and is rotatably situated with respect thereto. 
         [0030]    Pendulum flange  34  of centrifugal pendulum  12  accommodates, in a radially outer section, two pendulum masses  38 , which are situated axially opposite each other and are connected to each other via a spacer bolt  40 , spacer bolt  40  engaging with pendulum flange  34  through an arc-shaped cutout  42 . 
         [0031]      FIG. 2  shows a perspective view of centrifugal pendulum  12 , and  FIG. 3  shows a cutout (shown by the dashed line) of centrifugal pendulum  12 , marked in  FIG. 2  and identified by “C.” For the sake of better clarity, not all pendulum masses  38  are illustrated in  FIGS. 2 and 3 . As explained above, spacer bolt  40  engages with arc-shaped cutout  44  and thus connects pendulum masses  38  situated on both sides of pendulum flange  34 . Cutout  44  illustrated in  FIG. 3  has an arc-shaped cutout contour  46 , which limits a mobility of spacer bolt  40  by striking against cutout contour  46  with an outer circumferential surface  50  of spacer bolt  40 . 
         [0032]      FIG. 4  shows a sectional view of a spacer bolt  40  according to one special specific embodiment of the present invention. The section runs along section line A-A illustrated in  FIG. 1 . Spacer bolt  40  has a spacer bolt body  51  of a rotationally symmetrical design, including a longitudinal axis  52 , which may also be a rotation axis of spacer bolt  40 , depending on the fastening of spacer bolt  40  to pendulum masses  38 . Spacer bolt body  51  has two fastening areas  54 , on which spacer bolt body  51  is connected to pendulum masses  38 . Stop area  56  is situated between fastening areas  54 . Stop area  56  has a larger diameter than the two fastening areas  54 , which are adjacent to stop area  56  on the right and the left. 
         [0033]    Spacer bolt body  51  has a circumferential surface  58  in stop area  56 , which has a cylindrical design and has a chamfer  60  situated on each of its lateral edges in the direction of fastening area  54 . A damping system  62  is provided radially on the outside of circumferential surface  58  of spacer bolt body  51 . Damping system  62  of spacer bolt  40  includes a damping element  64  of an annular design, which is situated on circumferential surface  58  of spacer bolt body  51 . 
         [0034]    Damping element  64  has an essentially rectangular cross section, bevels  65  being provided on outer circumferential surface  50 . Damping element  64  is limited laterally in the axial direction by a stabilizing element  66 . Stabilizing element  66  is situated in direct contact with a particular front surface  68  of damping element  64 . The side surfaces of damping element  64  or stabilizing element  66  situated perpendicularly in the axial direction of longitudinal axis  52  are referred to as front surface  68  of stabilizing element  66 . 
         [0035]    For easier assembly, front surface  68  of damping element  64  is oriented perpendicularly to longitudinal axis  52  of spacer bolt  40 . Stabilizing element  66  has a smaller outer diameter than damping element  64 . This initially prevents stabilizing elements  66  from striking pendulum flange  34  or cutout contour  46  of cutout  44 , so that the impact contact initially takes place by damping element  64  striking cutout contour  46  of pendulum flange  34 . 
         [0036]    When damping element  64  strikes cutout contour  46  of pendulum flange  34 , a compression of damping element  64  occurs. To avoid or reduce an overload, due to the compression, stabilizing element  66  is able to limit the compression of damping element  64 , for example in that stabilizing element  66  strikes cutout contour  46  when damping element  64  reaches a certain compression. 
         [0037]    Due to the lateral limitation of damping element  64  by laterally situated stabilizing elements  66 , a lateral deflection of damping element  64  is avoided when outer circumferential surface  50  strikes cutout contour  46  of pendulum flange  34 . A possible breaking and cracking of damping element  64  is avoided thereby, so that spacer bolt  40  is more durable than known spacer bolts. The impact noise is also significantly reduced. 
         [0038]    Damping element  64  may be made of an elastic material, in particular rubber. 
         [0039]    Stabilizing elements  66  and damping element  64  have the same inner diameter, which is selected in such a way that damping element  64  and stabilizing elements  66  may be fastened to circumferential surface  58  of spacer bolt body  51  with the aid of a clearance fit. 
         [0040]    The clearance fit ensures that damping system  62  is easily rotatably seated on spacer bolt body  51 . For axially securing damping system  62 , the latter is fixed in the assembled state in stop area  56  of spacer bolt body  51  by laterally situated pendulum masses  38 . 
         [0041]    Damping elements  64  may be connected to stabilizing element  66  using vulcanization or another integral and form-fitting connection. If damping element  64  is connected to stabilizing element  66  using vulcanization, this has the advantage that a compression stress or an internal stress may be built up in damping element  64  during vulcanization, which is maintained after the vulcanization operation. The introduced internal stress results in the fact that, when damping element  64  strikes cutout contour  46  of cutout  44  directly, the internal stress, which is aimed oppositely to the introduced impact force or impact stress induced thereby, at least partially compensates for the impact stress, so that a dynamic damping capability and an effective rigidity of damping system  62  are increased. 
         [0042]    In this way, damping element  64  or damping system  62  may be subjected to a higher impact stress, or it has a longer service life as a result thereof. The assembly security of damping system  62  on spacer bolt body  51  is also improved. 
         [0043]      FIG. 5  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. Stabilizing element  66  is designed as a single piece with spacer bolt body  51 . 
         [0044]      FIG. 6  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. In this case, a stabilizing element  66  is introduced centrally between axially adjacent damping elements  64 . Stabilizing element  66  is designed to form a single piece with spacer bolt body  51 . 
         [0045]      FIG. 7  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. Stabilizing element  66  is introduced as a separate component centrally between axially adjacent damping elements  64 . 
         [0046]      FIG. 8  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. In this case, a stabilizing element  66  encompasses a damping element  64  on an outer circumference and in sections on the front surfaces of damping element  64 . Stabilizing element  66  has a U-shaped design. Stabilizing element  66  limits a compression of damping element  64  due to an impact on spacer bolt body  51 . 
         [0047]      FIG. 9  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. A stabilizing element  66  encompasses damping element  64  on an inner circumference which has a U-shaped design. Another stabilizing element  66  encompasses a radial outer circumference of damping element  64 . If a maximum compression is reached, an impact of the two stabilizing elements  66  against each other limits further compression. 
         [0048]      FIG. 10  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. In this case, a stabilizing element  66  encompasses a damping element  64  on an inner circumference and in sections on the front surfaces of damping element  64 . Stabilizing element  66  has a U-shaped design. Stabilizing element  66  limits a compression of damping element  64  due to an impact on cutout contour  46 . 
         [0049]      FIG. 11  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. A stabilizing element  66 , which encompasses damping element  64  at least in sections on an outer circumference and also at least in sections on a front surface, has an L-shaped design. If a maximum compression is reached, an impact of the radially inwardly oriented section of stabilizing element  66  on spacer bolt body  51  limits a further compression of damping element  64 . 
         [0050]      FIG. 12  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. A stabilizing element  66 , which encompasses damping element  64  at least in sections on an outer circumference and also at least in sections on a front surface, has an L-shaped design. Another stabilizing element  66  encompasses damping element  64  at least in sections on an inner circumference and at least in sections on the other front surface of damping element  64 . If a maximum compression is reached, an impact of the radially inwardly oriented section of stabilizing element  66  on other stabilizing element  66  as well as vice versa limits a further compression of damping element  64 . 
         [0051]      FIG. 13  shows a detail of a cross section of a centrifugal pendulum, including a spacer bolt  40  in another special specific embodiment of the present invention. A stabilizing element  66  encompasses an outer circumference of damping element  64  at least in sections. If a maximum compression is reached, an impact of stabilizing element  66  on a shoulder  70  in pendulum mass  38  limits further compression. Shoulder  70  may be provided as a single piece from pendulum mass  38 , or it may be implemented as a separate component fastened thereto. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           10  torsional vibration damper 
           12  centrifugal pendulum 
           14  damper input part 
           16  disk carrier 
           18  output hub 
           20  toothing 
           22  energy storage element 
           24  damper intermediate part 
           26  energy storage element 
           28  damper output part 
           30  disk part 
           32  disk part 
           34  pendulum flange 
           36  turbine hub 
           38  pendulum mass 
           40  spacer bolt 
           42  cutout 
           44  cutout 
           46  cutout contour 
           50  circumferential surface 
           51  spacer bolt body 
           52  longitudinal axis 
           54  fastening area 
           56  stop area 
           58  circumferential surface 
           60  chamfer 
           62  damping system 
           64  damping element 
           65  bevels 
           66  stabilizing element 
           68  front surface 
           70  shoulder

Technology Classification (CPC): 8