Abstract:
A pendulum absorber fixed to the crankshaft of an engine comprises a pendulum and a pendulum carrier attached to the pendulum carrier attachment boss of the crankshaft. The first preferred embodiment provides a crankshaft web having spaced apart part pendulum carrier attachment bosses that define a carrier groove. The second preferred embodiment provides an arrangement similar to that of the first embodiment but the attachment bosses extend further away from the web. The third preferred embodiment provides a pendulum carrier having a flat portion and a cylindrical portion. The fourth preferred embodiment provides a carrier engagement portion that includes a deck and two lateral attachment bosses having curved surfaces. The carrier includes two outwardly-extending attachment arms. The fifth preferred embodiment provides a web having a pendulum carrier engagement portion that includes a machined groove and machined attachment bosses. The pendulum carrier includes attachment arms that engage the machined attachment bosses.

Description:
TECHNICAL FIELD 
       [0001]    The disclosed inventive concept relates generally to absorbers to reduce torsional vibration in an internal combustion engine. More particularly, the disclosed inventive concept relates to arrangements for attaching the absorbers in the form of pendulums to a crankshaft. 
       BACKGROUND OF THE INVENTION 
       [0002]    Internal combustion engines having a relatively small number of cylinders provide automobile makers with an attractive solution to the need for improved fuel economy. In order to compensate for reduction of cubic capacity vehicle manufacturers developed technologies to improve engine power, such as direct fuel injection, turbocharging, and variable timing for inlet and exhaust camshafts. In this way six- and eight-cylinder engines can be scaled down without losing available horsepower. 
         [0003]    An undesirable consequence of engines with a small number of cylinders is high crankshaft torsional vibration and high engine block vibration caused by forces, such as first and second order forces, that are not cancelled. Such vibrations are ultimately transmitted through the engine mounts and driveline to the vehicle structure. 
         [0004]    Engineers managed these vibrations to one extent or another through a variety of approaches, many of which increase the cost of construction and reduce fuel economy. One accepted solution to overcome excessive vibration is the provision of one or more pendulums on the crankshaft to lower the torsional vibration of the crankshaft and the consequent driveline vibration. Such crankshaft-mounted pendulums function as vibration absorbers as they are tuned to address and thus cancel out vibrations generated by crankshaft rotation, thus smoothing torque output of the crankshafts. This approach is taken as well by designers of some airplane piston engines where the pendulums smooth output torque and reduce rigid body motion. 
         [0005]    Pendulum vibration absorbers are attached to the engine crankshaft web using pendulum carriers. The pendulum carriers are themselves attached to the crankshaft web according to a wide variety of attachment methods, including mechanically fastening. In many instances, the crankshaft itself requires excessive machining to accommodate the pendulum carrier. 
         [0006]    While the concept of attaching a pendulum to a crankshaft provides smoother engine performance, known methods of attaching the crankshaft pendulum carrier to the crankshaft are overly complex, resulting in either expensive pendulum carrier production or expensive crankshaft preparation or both. Accordingly, a new approach to the attachment of the pendulum carrier to the crankshaft web is needed to address the problems associated with known arrangements without compromising the desired reduction of torsional vibration produced by the internal combustion engine. 
       SUMMARY OF THE INVENTION 
       [0007]    The different embodiments of the disclosed inventive concept provide practical and cost-effective solutions to the challenges faced when attaching a pendulum carrier to a crankshaft according to known approaches. Each of the various embodiments illustrated and described herein provides an advantage over the prior art by simplifying methods of attachment without compromising operating performance of the crankshaft pendulum. 
         [0008]    The first preferred embodiment of the disclosed inventive concept provides a crankshaft web having spaced apart part pendulum carrier attachment bosses that define a carrier groove. The pendulum carrier is fitted into the groove and is mechanically attached to the web by, for example, pressed-in pins. A long drill is used to form attachment holes in the pendulum carrier attachment bosses. 
         [0009]    The second preferred embodiment of the disclosed inventive concept provides an arrangement similar to that of the first preferred embodiment but the pendulum carrier attachment bosses extend further away from the crankshaft web so as to avoid the possibility of drilling into the thrust face of the crankshaft during production. 
         [0010]    The third preferred embodiment of the disclosed inventive concept provides a pendulum carrier having a flat portion and a cylindrical portion. The crankshaft web includes an attachment groove having a cylindrical portion. The pendulum carrier is inserted into the attachment groove such that the cylindrical portion of the carrier fits within the cylindrical portion of the attachment groove. The cylindrical portion of the pendulum carrier includes an end cap that restricts movement within the attachment groove. A fastener such as a bolt is installed at the opposite end of the pendulum carrier to fix it to the crankshaft web. 
         [0011]    The fourth preferred embodiment of the disclosed inventive concept eliminates the need for machining a groove into the crankshaft web by providing a carrier engagement portion that includes a deck and two lateral attachment bosses having curved surfaces. The pendulum carrier includes two attachment arms that extend outward from the carrier for engagement with the engagement portion of the crankshaft web. A mechanical fastener, such as bolt, is used to lock the pendulum carrier against the attachment bosses of the carrier engagement portion. The curved surfaces of the attachment bosses carry the load of the pendulum assembly. No drilling of the web is required. 
         [0012]    The fifth preferred embodiment of the disclosed inventive concept includes a crankshaft web having a pendulum carrier engagement portion. The pendulum carrier engagement portion includes a machined groove and machined attachment bosses. The pendulum carrier includes attachment arms that extend downward for engagement with the machined attachment bosses of the pendulum carrier engagement portion of the crankshaft web. 
         [0013]    The above advantages and other advantages and features will be readily apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention wherein: 
           [0015]      FIG. 1  is a side elevational view of a crankshaft having an arrangement for attaching pendulum carriers thereto according to a first preferred embodiment of the disclosed inventive concept; 
           [0016]      FIG. 2  is a perspective view of a portion of the crankshaft shown in  FIG. 1 ; 
           [0017]      FIG. 3  is a perspective view of a pendulum carrier for use with the crankshaft shown in  FIG. 1  according to the first preferred embodiment of the disclosed inventive concept; 
           [0018]      FIG. 4  is a perspective view of the crankshaft of  FIG. 1  illustrating the drill paths through the thrust faces required to form the attachment holes for mechanically fastening the pendulum carriers to the crankshaft according to the embodiment of  FIG. 1 ; 
           [0019]      FIG. 5  is a close up view of a portion of the crankshaft shown in  FIG. 1  illustrating a single drill path; 
           [0020]      FIG. 6  is a close up view of a portion of the crankshaft shown in  FIG. 1  illustrating a single drill path dictated by the flywheel bolt holes; 
           [0021]      FIG. 7  is a partial end view of the intersection of a portion of the pendulum carrier according to the first embodiment of the disclosed inventive concept fitted into the pendulum carrier groove of a crankshaft in which a method of attaching the pendulum carrier to the crankshaft is illustrated; 
           [0022]      FIG. 8  is a close up view of a portion of the crankshaft illustrating a second preferred embodiment of the disclosed inventive concept in which the pendulum attachment bosses have been extended from the crankshaft webs compared with the position of the bosses in the first preferred embodiment of the disclosed inventive concept; 
           [0023]      FIG. 9  is an end view of the second preferred embodiment of the disclosed inventive concept illustrated in  FIG. 8 ; 
           [0024]      FIG. 10  illustrates a perspective view of a portion of a crankshaft having a pendulum carrier attached thereto according to a third preferred embodiment of the disclosed inventive concept viewed from the end cap side; 
           [0025]      FIG. 11  illustrates a perspective view of a portion of a crankshaft having a pendulum carrier attached thereto according to the third preferred embodiment of the disclosed inventive concept viewed from the fastener side; 
           [0026]      FIG. 12  is a perspective view illustrating a pendulum attached to the pendulum carrier of the third preferred embodiment of the disclosed inventive concept; 
           [0027]      FIG. 13  is a side view of the pendulum carrier fitted to a crankshaft according to the third preferred embodiment of the disclosed inventive concept; 
           [0028]      FIG. 14  illustrates a perspective view of a portion of a crankshaft having a pendulum carrier attached thereto according to a fourth preferred embodiment of the disclosed inventive concept; 
           [0029]      FIG. 15  illustrates a perspective view of a portion of a crankshaft to which a pendulum carrier may be attached according to a fifth preferred embodiment of the disclosed inventive concept; 
           [0030]      FIG. 16  is an end view of the crankshaft shown in  FIG. 15  illustrating the pendulum carrier attached to the crankshaft; 
           [0031]      FIG. 17  is a perspective view of the crankshaft pendulum of the fifth preferred embodiment attached to a crankshaft and having a pendulum attached thereto; and 
           [0032]      FIG. 18  is an end view of the crankshaft pendulum of the fifth preferred embodiment attached to a crankshaft and having a pendulum attached thereto. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0033]    In the following figures, the same reference numerals will be used to refer to the same components. In the following description, various operating parameters and components are described for different constructed embodiments. These specific parameters and components are included as examples and are not meant to be limiting. 
         [0034]    The figures illustrate five preferred embodiments of the disclosed inventive concept. Particularly,  FIGS. 1 through 7  illustrate a first preferred embodiment of the disclosed inventive concept.  FIGS. 8 and 9  illustrate a second preferred embodiment of the disclosed inventive concept.  FIGS. 10 through 13  illustrate a third preferred embodiment of the disclosed inventive concept.  FIG. 14  illustrates a fourth preferred embodiment of the disclosed inventive concept. And  FIGS. 15 through 18  illustrate a fifth preferred embodiment of the disclosed inventive concept. It is to be understood that the overall configurations of the illustrated crankshaft assemblies shown in the figures is set forth for suggestive purposes only as the overall configuration may be altered from that illustrated without deviating from the spirit or scope of the invention. 
       First Embodiment 
       [0035]    Referring to  FIG. 1 , a side view of a crankshaft assembly having a pendulum and pendulum carrier according to a first embodiment of the disclosed inventive concept is illustrated. The crankshaft assembly, generally illustrated as  10 , includes a crankshaft  12  having a rotational axis  14 . Rotation of the crankshaft  12  about its rotational axis  14  is made possible by the provision of main journals  16 ,  16 ′,  16 ″,  16 ′″ and  16 ″″. The journals  16 ,  16 ′,  16 ″,  16 ′″ and  16 ″″ are integrally formed as part of the crankshaft  12  and are restrained within the engine block (not shown) by crankshaft bearings (not shown). 
         [0036]    The connecting rods (not shown) are attached as is known in the art to rod journals  18 ,  18 ′,  18 ″, and  18 ′″ by rod bearings (not shown). The rod journals  18 ,  18 ′,  18 ″, and  18 ′″ are integrally formed on the crankshaft  12 , again as is known in the art. 
         [0037]    The crankshaft  12  includes a first end  20  and a second end  22 . Conventionally provided extending from one end, in this case the first end  20 , is a post  24 . The post  24  serves as a mount for any number of engine components, such as a fan belt pulley and a drive mechanism for a camshaft. These components are not shown but these components and their methods of attachment are known to those skilled in the art. 
         [0038]    Conventionally attached to the other end of the crankshaft  12 , in this case the second end  22 , is a flywheel (not shown) that attaches to the flywheel flange  23 . The flywheel, which assists in reducing torsional fluctuations in the crankshaft  12 , is in operative engagement with the drive shaft or transaxle of the vehicle. 
         [0039]    To each side of the rod journal  18  is provided a spaced apart pair of crankshaft webs  26  and  26 ′. To each side of the rod journal  18 ′ is provided a spaced apart pair of crankshaft webs  28  and  28 ′. To one side of the rod journal  18 ″ is provided a crankshaft web  30 . To each side of the rod journal  18 ′″ is provided a spaced apart pair of crankshaft webs  32  and  32 ′. 
         [0040]    The crankshaft webs include grooves for attachment of pendulum carriers according to the disclosed inventive concept. Particularly, a pendulum carrier attachment groove  34  is formed at one end of the crankshaft web  26 . A pendulum carrier attachment groove  36  is formed at one end of the crankshaft web  26 ′. A pendulum carrier attachment groove  38  is formed at one end of the crankshaft web  28 . A pendulum carrier attachment groove  40  is formed at one end of the crankshaft web  28 ′. A pendulum carrier attachment groove  42  is formed at one end of the crankshaft web  30 . And a pendulum carrier attachment groove  44  is formed at one end of the crankshaft web  32 ′. 
         [0041]      FIG. 2  illustrates details of the arrangement for attaching a crankshaft pendulum carrier to a crankshaft according to a first embodiment of the disclosed inventive concept. Extending from the crankshaft web  26  is a first pair of spaced part pendulum carrier attachment bosses  46  and  46 ′. Also extending from the crankshaft web  26  is a second pair of spaced part pendulum carrier attachment bosses  48  and  48 ′. The pendulum carrier groove  34  is formed between the pendulum carrier attachment bosses  46  and  46 ′ and the bosses  48  and  48 ′. Extending from the crankshaft web  26 ′ is a first pair of spaced part pendulum carrier attachment bosses  50  and  50 ′. Also extending from the crankshaft web  26 ′ is a second pair of spaced part pendulum carrier attachment bosses  52  and  52 ′. The pendulum carrier groove  36  is formed between the pendulum carrier attachment bosses  50  and  50 ′ and the bosses  52  and  52 ′. Pendulum carrier attachment bosses are also formed on the crankshaft webs  28 ,  28 ′,  30 , and  32 ′. 
         [0042]    A pendulum carrier  54 , shown attached to the crankshaft web  26  in  FIGS. 1 and 2  and by itself in  FIG. 3 , is positioned within the pendulum carrier groove formed in the crankshaft web. The pendulum carrier  54  is of a one plane, one-piece, flat design and can thus be inexpensively and easily manufactured by cold forming or other stamping techniques. A crankshaft pendulum (not shown) is movably attached to the pendulum carrier  54 . 
         [0043]    A pair of kidney-shaped cycloid pathways  56  and  56 ′ is formed either during the cold forging process or by machining in the pendulum carrier  54 . Pendulum rollers (not shown) are provided in the cycloid pathways  56  and  56 ′. A pair of fastener holes  58  and  58 ′ for attachment to the pendulum carrier attachment bosses are formed in the pendulum carrier  54 . 
         [0044]    The pendulum carriers  54  are attached to the crankshaft  12  by fasteners, such as rivets or other mechanical fasteners, as will be discussed below relative to  FIG. 9 . Proper alignment of the fastener holes through the webbing and the pendulum carriers is desired.  FIGS. 4 through 6  illustrate the drill paths needed for the formation of properly aligned fastener holes. 
         [0045]    Referring to  FIGS. 4 through 6 , a first drill path D 1  is formed through the pendulum carrier attachment bosses  46 ,  46 ′,  50  and  50 ′ during the manufacturing process of the crankshaft  12 . A second drill path D 2  is formed during the manufacturing process through a pair of opposed pendulum carrier attachment bosses  66  and  66 ′ between which the pendulum carrier attachment groove  38  is formed, through a pair of opposed pendulum carrier attachment bosses  68  and  68 ′ through which the pendulum carrier attachment groove  40  is formed, and through a pair of opposed pendulum carrier attachment bosses  70  and  70 ′ through which the pendulum carrier attachment groove  42  is formed. An indented area  72  is formed on the web  26  to allow for the passage of a drill bit (not shown) along the drill path D 2 . In addition, an indented area  72 ′ is formed on the web  26 ′ to allow for the passage of the same drill bit (not shown) along the drill path D 2 . 
         [0046]    A third drill path D 3  is formed through a pair of opposed pendulum carrier attachment bosses  74  and  74 ′ between which the pendulum carrier attachment groove  44  is formed and through a bolt hole  76  formed through the flywheel flange  23 . While drill paths D 1 , D 2  and D 3  are illustrated, it is to be understood that a like number of drill paths exist symmetrically on the far side of the crankshaft in the same but opposite positions as D 1 , D 2  and D 3 . 
         [0047]    Each pendulum carrier is attached to pendulum carrier attachment bosses formed on the crankshaft webs by elongated, mechanical fasteners positioned through the pendulum carriers and into the pendulum carrier attachment bosses. Particularly, and as illustrated in  FIG. 7 , the pendulum carrier  54 , fitted into the pendulum carrier groove  34 , is attached to the spaced part pendulum carrier attachment bosses  48  and  48 ′ by a mechanical fastener, such as a pressed-in pin  80 . The pressed-in pin  80  passes through holes formed in the pendulum carrier attachment bosses  48  and  48 ′. The pressed-in pin  80  may be of a variety of diameters, though a non-limiting diameter may be 8.0 mm. The pressed-in pin  80  is pressed in to assure good attachment by way of an interference fit. This method of attachment, coupled with the tight fit of the pendulum carrier  54  to the pendulum carrier attachment web  26 , restricts movement of the pendulum assembly relative to the crankshaft  12 . 
         [0048]    A number of tools may be used for pressing the pressed-in pin  80  through the holes formed the pendulum carrier attachment bosses  48  and  48 ′. One such tool is a crimping tool having crimps  82  and  82 ′ that simultaneously apply pressure to the inserted pin  80 . This approach is suggestive and is not intended as being limiting. 
       Second Embodiment 
       [0049]    The manufacturing challenge of the first embodiment discussed above is that the formation of the holes needed for fastening the pendulum carrier to the crankshaft web may result in the drill contacting and possibly passing through the crankshaft thrust face. This is particularly the case when the operator relies on the flywheel flange  23  when following the third drill path D 3  as shown in  FIG. 6 . 
         [0050]    A solution to this challenge is illustrated in  FIGS. 8 and 9  in which a second preferred embodiment of the disclosed inventive concept is illustrated. 
         [0051]    Referring to  FIG. 8 , a perspective view of a crankshaft assembly having a pendulum and pendulum carrier according to a second embodiment of the disclosed inventive concept is illustrated. The crankshaft assembly, generally illustrated as  110 , includes a crankshaft  112  having main journals  114  and  114 ′. The main journals  114  and  114 ′ are integrally formed as part of the crankshaft  112  and are restrained within the engine block (not shown) by crankshaft bearings (not shown). The connecting rods (not shown) are attached as is known in the art to connecting rod journals  118  and  118 ′ by rod bearings (not shown). The connecting rod journals  118  and  118 ′ are integrally formed on the crankshaft  112 , again as is known in the art. 
         [0052]    To one side of the main journal  114  is provided a crankshaft web  120 . To each side of the connecting rod journal  118 ′ is provided a spaced apart pair of crankshaft webs  122  and  122 ′. To one side of the main journal  114 ″ is provided a crankshaft web  124 . 
         [0053]    The crankshaft webs include grooves for attachment of pendulum carriers according to the disclosed inventive concept. Particularly, a pendulum carrier attachment groove  126  is formed at one end of the crankshaft web  120 . A pendulum carrier attachment groove  128  is formed at both ends of the crankshaft web  122 . A pendulum carrier attachment groove  130  is formed at both ends of the crankshaft web  122 ′. A pendulum carrier attachment groove  132  is formed at both ends of the crankshaft web  124 . 
         [0054]    Extending from the crankshaft web  120  is a first pair of extended, spaced part pendulum carrier attachment bosses  134  and  134 ′. Extending from the crankshaft web  122  is a pair of extended, spaced part pendulum carrier attachment bosses  136  and  136 ′. Extending from the crankshaft web  122 ′ is a pair of extended, spaced apart pendulum carrier attachment bosses  138  and  138 ′. Extending from the crankshaft web  124  is a pair of extended, spaced apart pendulum carrier attachment bosses  140  and  140 ′. 
         [0055]      FIG. 9  illustrates an end view of the crankshaft assembly  110 . The end of the crankshaft  112  includes flywheel flange  142  to which the flywheel (not shown) is attached. Behind the flywheel flange  142  is a crankshaft web  144  that includes a first extended pendulum carrier attachment boss  146  and a second extended pendulum carrier attachment boss  148 . 
         [0056]    As illustrated in  FIGS. 8 and 9 , the extended attachment bosses enable the manufacturer to drill the holes needed for the mechanical fasteners without contacting the thrust face of the crankshaft. 
       Third Embodiment 
       [0057]      FIGS. 10 through 13  illustrate a third embodiment of the disclosed inventive concept for attaching a crankshaft pendulum carrier to a crankshaft. Referring to  FIGS. 10 and 11 , perspective views of a crankshaft assembly having a pendulum and pendulum carrier according to a third embodiment of the disclosed inventive concept is illustrated. The crankshaft assembly, generally illustrated as  150 , includes a crankshaft  152  having main journals  154  and  154 ′. The main journals  114  and  114 ′ are integrally formed as part of the crankshaft  112  and are restrained within the engine block (not shown) by crankshaft bearings (not shown). A connecting rod (not shown) is attached as is known in the art to a connecting rod journal  156  by a rod bearing (not shown). 
         [0058]    To each side of the connecting rod journal  156  is provided a spaced apart pair of crankshaft webs  158  and  158 ′. The crankshaft webs  158  and  158 ′ include grooves for attachment of pendulum carriers according to the disclosed inventive concept. Particularly, a pendulum carrier attachment groove  160  is formed at one end of the crankshaft web  158 . A pendulum carrier attachment groove  162  is formed at one end of the crankshaft web  158 ′. 
         [0059]    The pendulum carrier attachment groove  160  includes a cylindrical portion  164  and a slotted portion  166 . The pendulum carrier attachment groove  162  includes a cylindrical portion  168  and a slotted portion  170 . The cylindrical portion  168  includes a internal shoulder  167  (shown in sectional view in  FIG. 13 ). 
         [0060]      FIG. 12  illustrates a pendulum assembly  172  for use with the crankshaft assembly  150  of the third preferred embodiment of the disclosed inventive concept. The pendulum assembly  172  includes a pendulum  174  and a pendulum carrier  176  to which the pendulum  174  is movably attached. The pendulum carrier  176  includes a pair of pendulum attachment ears  178  and  178 ′ (illustrated in  FIGS. 10, 11 and 13 ) and a cylindrical attachment body  180 . The cylindrical attachment body  180  is either integrally formed with the pendulum carrier  176  by cold forging or may be attached to a flat stamping by welding. The attachment body  180  includes a bolt end  182  having a bolt  184  and a cap end  186 . 
         [0061]    To install the pendulum carrier  176  into the pendulum carrier attachment channel, the attachment body  180  is inserted bolt end  182  first into the groove until the bolt end  182  abuts the internal shoulder  167 . The installer then installs the bolt  184  into the bolt end  182 , thus fixing the pendulum carrier relative to the crankshaft web. In operation, the operating load is carried by the upper portion of the cylindrical attachment body  180 . The third preferred embodiment of the disclosed inventive concept provides a simple and inexpensive solution to the challenge of attaching a pendulum carrier to a crankshaft web without the need of long drilling of the crankshaft itself. 
       Fourth Embodiment 
       [0062]      FIG. 14  illustrates a fourth embodiment of the disclosed inventive concept for attaching a crankshaft pendulum carrier to a crankshaft. In  FIG. 14 , a perspective view of a crankshaft assembly according to the fourth preferred embodiment of the disclosed inventive concept is generally illustrated as  200 . The crankshaft assembly  200  includes a crankshaft  202  having main journals  204  and  204 ′. The main journals  204  and  204 ′ are integrally formed as part of the crankshaft  112  and are restrained within the engine block (not shown) by crankshaft bearings (not shown). A connecting rod (not shown) is attached as is known in the art to a connecting rod journal  206  by a rod bearing (not shown). 
         [0063]    To each side of the connecting rod journal  206  is provided a spaced apart pair of crankshaft webs  208  and  208 ′. The crankshaft webs  208  and  208 ′ include pendulum carrier engagement portions for attachment of pendulum carriers according to the disclosed inventive concept. Particularly, a pendulum carrier engagement portion  210  is formed at one end of the crankshaft web  208 . A pendulum carrier engagement portion  212  is formed at one end of the crankshaft web  208 ′. 
         [0064]    The pendulum carrier engagement portion  210  includes a deck  214  and two lateral attachment bosses  216  and  216 ′. The pendulum carrier engagement portion  212  includes a deck  218  and two lateral attachment bosses  220  and  220 ′. 
         [0065]    A one-piece, cold forged steel pendulum carrier  222  includes a pair of pendulum attachment ears  224  and  224 ′. The pendulum carrier  222  further includes attachment arms that extend outward for engagement with the engagement portion of the crankshaft web. As illustrated in  FIG. 14 , the pendulum carrier  222  includes an attachment arm  226  having a mechanical fastener, such as bolt  228 . 
         [0066]    Attachment of the pendulum carrier  222  to the engagement portion  210  occurs when the installer slips the pendulum carrier  222  over the engagement portion  210  such that the pendulum carrier  222  is flush against the deck  214  and the attachment arm  226  engages the attachment boss  216 ′. The curved surface of the attachment boss carries the load of the pendulum assembly. No drilling of the web is required. 
       Fifth Embodiment 
       [0067]    Referring to  FIGS. 15 through 18 , a fifth embodiment of the disclosed inventive concept for attaching a pendulum carrier to a crankshaft is illustrated. Particularly, and referring to  FIG. 15 , a portion of a crankshaft assembly, generally illustrated as  230 , is shown. The crankshaft assembly  230  includes a crankshaft  232  having a connecting rod journal  234 . A connecting rod (not shown) is attached to the connecting rod journal  234  as is known in the art. 
         [0068]    To each side of the connecting rod journal  234  is provided a spaced apart pair of crankshaft webs  236  and  236 ′. The crankshaft webs  236  and  236 ′ include pendulum carrier engagement portions for attachment of pendulum carriers according to the disclosed inventive concept. As shown in  FIG. 15 , a pendulum carrier engagement portion  238  is formed at one end of the crankshaft web  236 . The pendulum carrier engagement portion  238  includes a machined groove  240  (machined into the cast face of the pendulum carrier engagement portion  238 ) and machined attachment bosses  242  and  242 ′. 
         [0069]    A cold forged steel pendulum carrier  244  includes a pair of pendulum attachment ears  246  and  246 ′. The pendulum carrier  244  further includes attachment arms  248  and  248 ′ that extend downward for engagement with the machined attachment bosses  242  and  242 ′ of the pendulum carrier engagement portion  238  of the crankshaft web  236 . The attachment arms  248  and  248 ′ may be welded to the carrier  244 . 
         [0070]    On assembly, the pendulum carrier  244  is positioned onto the engagement portion  238  such that a portion of the pendulum carrier  244  is slotted into the machined groove  240  and the attachment arms  248  and  248 ′ are positioned respectively over the attachment bosses  242  and  242 ′ as illustrated in  FIG. 16 . Thereafter, mechanical fasteners, such as shoulder bolts  250  and  250 ′, are used to fix the pendulum carrier  244  to the pendulum carrier engagement portion  238  of the crankshaft web  236 . As an alternative to shoulder bolts, mechanical attachment may also be achieved by use of rivets or pressed pins. 
         [0071]      FIGS. 17 and 18  respectively illustrate perspective and end views of the pendulum carrier  244  attached to the crankshaft web  236 . In each figure, a pendulum  252  is shown movably attached to the pendulum carrier  244 . 
         [0072]    The pendulum carrier attachment arrangement according to the fifth preferred embodiment of the disclosed inventive concept provides several advantages over known approaches. First, the illustrated and described configuration provides a robust design with minimal manufacturing costs. Second, the crankshaft is of either as-cast or as-forged design with minimal machining except for the formation of the attachment bosses and the groove. Third, this design eliminates the need for pressed fits. Fourth, this design eliminates the need for long drillings. Fifth, this design provides axial support to the pendulum carrier, thereby eliminating axial movement during engine operation. 
         [0073]    One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following claims.