Patent Abstract:
A link assembly for a vehicle, comprising a longitudinal link which has an upper link element and a lower link element, and at least one bushing receptacle for receiving a bearing bushing, wherein the bushing receptacle is at least partially integrated in at least one of the link elements, or is connectable as a separate part to the upper link element and the lower link element.

Full Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a link assembly for a vehicle, in particular for a commercial vehicle. 
         [0002]    A link assembly serves for suspension of a vehicle axle on the vehicle frame, wherein the vehicle axle in the case of commercial vehicles is customarily a rigid axle. The use of longitudinal links which substantially extend in the longitudinal direction of the vehicle and are mounted about a pivot axis running transversely with respect to the vehicle axle is known. A first end of the longitudinal link is arranged pivotably here on the vehicle frame, in particular on a bearing bracket. A second end of the longitudinal link receives the vehicle axle. The vehicle axle can be mounted on the frame of the vehicle in a sprung or damped manner by means of additional spring elements and/or damping elements. 
         [0003]    A link assembly for mounting a vehicle axle on a vehicle frame is described in U.S. Pat. No. 5,690,353 A. The link assembly here comprises a longitudinal link of two-part design. The two-part longitudinal link is mounted on a bearing bolt of the vehicle frame via a specially shaped bearing bushing. The invention is based on the object of providing a link assembly which is of particularly stable construction and can be mounted as simply as possible. 
       SUMMARY OF THE INVENTION 
       [0004]    The link assembly comprises a longitudinal link that has an upper link element (link upper part) and a lower link element (link lower part). The link assembly furthermore comprises at least one bushing receptacle for receiving a bearing bushing. The bushing receptacle is at least partially integrated in at least one of the link elements (in the link upper part and/or in the link lower part). Alternatively, the bushing receptacle is connectable as a separate part to the upper link element and to the lower link element (to the link upper part and to the link lower part). The invention is based on a multi-part, in particular two-part longitudinal link which has an upper link element and a lower link element which, connected to each other, form the longitudinal link. It is preferred here for both the upper link element and the lower link element to have a recess for a vehicle axle, and therefore the vehicle axle can be arranged between the upper link element and the lower link element. By this means, the vehicle axle does not need to be pushed in a complicated manner into a corresponding bore of the longitudinal link, and therefore the installation is considerably simplified in comparison to a single-part longitudinal link. The upper link element and the lower link element are fixedly connected to each other to form the longitudinal link. For this purpose, an integrally bonded connection is preferably provided, in particular in the region of the vehicle axle or in the region of the respective recesses in the link elements. Alternatively or additionally, there can also be a form-fitting and/or force-fitting connection. The vehicle axle is secured, preferably in an integrally bonded manner, on the link upper part and on the link lower part. A particularly preferred embodiment of an integrally bonded connection is a welded connection. The longitudinal link is secured on the vehicle or on the vehicle frame (bearing bracket) via a bearing bushing, for example a rubber ring, which receives a bearing journal. For this purpose, the longitudinal link has a bushing receptacle for receiving the bearing bushing. The bushing receptacle defines or surrounds an in particular cylindrical opening into which the bearing bushing is preferably pressed. The bushing receptacle is expediently closed circumferentially, i.e. is designed, for example, as a closed ring. 
         [0005]    According to a preferred embodiment of the invention, the bushing receptacle is integrated in one of the link elements, i.e. the link upper part or the link lower part. This should be understood as meaning in particular that at least part of the bushing receptacle forms an integral part of the corresponding link element. The bushing receptacle is therefore not a separate part secured to the link element, but rather is formed integrally with the link element. The corresponding link element has a recess or opening for receiving the bearing bushing or into which the bearing bushing is pressed. The bushing receptacle is therefore formed by corresponding shaping of the link element. The bushing receptacle can also be referred to as a pivot tube or can form a pivot tube. 
         [0006]    The link element is preferably a cast part. The bushing receptacle is preferably a region of the cast part but can be machined, optionally retrospectively. The bushing receptacle formed by forming a recess or opening in the link element is particularly stable and ensures reliable storage of the link assembly on the vehicle frame. In addition, the installation is particularly simple because of the two-part design of the link assembly. 
         [0007]    According to an alternatively preferred embodiment of the invention, the bushing receptacle is a separate, in particular annular part which is fastenable to fastening surfaces, which are provided for this purpose, of the link elements. In particular, an integrally bonded connection is provided between the link element (for example cast part) and the bushing receptacle. The link elements expediently each have a curved contact or connecting surface for bearing against a correspondingly curved outer surface of the annular bushing receptacle. The contact or connecting surface and the outer surface are preferably connected in a flat manner to each other. The flat connection between link element and bushing receptacle is particularly stable in comparison to a merely spot-type or linear connection. The contact surfaces of the link elements are preferably of circular-arc-shape design in cross section for interaction with the in particular cylindrical casing surface of the bushing receptacle. 
         [0008]    In a preferred embodiment of the invention, it is provided that the bushing receptacle is completely integrated in one of the link elements. It should be understood by this that the bushing receptacle is designed in such a manner that a bearing bushing which is accommodated therein exclusively contacts the upper link element or the lower link element. The corresponding link element in particular has a circumferentially closed opening for the bearing bushing. The in particular cylindrical opening is preferably surrounded by the cast material of the link element formed as a cast part. The opening is preferably bounded at the end of the link element by a curved wall. The curved wall preferably forms a circular-arc-shaped portion of a hollow cylinder. 
         [0009]    According to an embodiment of the invention, it is provided that the bushing receptacle is integrated in the upper link element and is connectable to the lower link element or, in the mounted state, is connected to the lower link element. The integration in the link element facing the vehicle achieves particularly good stability. The two link elements are connected to each other in the region of the bushing receptacle. 
         [0010]    It is preferably provided that the bushing receptacle has a curved, in particular cylindrical, outer surface or outer wall, and that the lower link element has a correspondingly curved abutment or connecting surface for placing against the curved outer surface or outer wall or for connecting to the curved outer surface or outer wall of the bushing receptacle. The outer wall has in particular a cylindrical outer surface. The abutment or connecting surface for connecting to the outer surface of the bushing receptacle preferably has a curved or circular-arc-shaped cross section. An integrally bonded connection is preferably provided. 
         [0011]    According to a further embodiment of the invention, the bushing receptacle is integrated in the lower link element and is connectable to the upper link element or, in the mounted state, is connected to the upper link element. 
         [0012]    It is preferably provided that the bushing receptacle has a curved, in particular cylindrical, outer surface or outer wall, and that the upper link element has a correspondingly curved abutment or connecting surface for placing against the curved outer surface or outer wall or for connecting to the curved outer surface or outer wall of the bushing receptacle. The outer wall has in particular a cylindrical outer surface. The abutment or connecting surface for connecting to the outer surface of the bushing receptacle preferably has a curved or circular-arc-shaped cross section. An integrally bonded connection is preferably provided. 
         [0013]    In a further preferred embodiment, the bushing receptacle is of multi-part design and has an upper shell and a lower shell. The upper shell of the in particular two-part bushing receptacle can be arranged, in particular fastened, for example, to the upper link element and the lower shell to the lower link element. Upper shell and lower shell preferably form a closed bushing receptacle when joined together, i.e. an in particular cylindrical opening with a closed casing surface. 
         [0014]    It is preferred that the upper shell of the bushing receptacle is integrated in the upper link element and the lower shell of the bushing receptacle is integrated in the lower link element. The upper link element therefore preferably has an upper shell which is formed integrally or as a single part therewith, and the lower link element has a corresponding lower shell. In other words, the upper link element has a first recess which is preferably partially circular or semicircular in cross section, and the lower link element has a second recess completing the circle. The recesses forming the bushing receptacle in the upper and lower link element are preferably formed directly in the cast material of the link element. 
         [0015]    In a further preferred embodiment of the invention, it is provided that the link elements surround an inner clearance in a curved manner and are connectable to each other in the region of the bushing receptacle via the bushing receptacle. The link elements are preferably connectable to each other directly, in particular in an integrally bonded manner (or are connected in the joined-together state) in the region of the vehicle axle and are connectable indirectly, via the bushing receptacle (or are connected in the joined-together state) in the region of the bushing receptacle. For this purpose, the link elements are each connectable, in particular in an integrally bonded manner, to the bushing receptacle. 
         [0016]    Overall, the invention can also be described as follows: 
         [0017]    A longitudinal link comprises two halves, namely an upper half and a lower half which, in the joined-together state, are connected to each other at a tubular pivot region (bushing receptacle). The tubular pivot region or the bushing receptacle bounds an opening for receiving a bearing bushing. There are different possibilities for connecting the two halves of the longitudinal link: 
         [0018]    A preferred connection consists in that the tube for the bearing bushing (the bushing receptacle) is integrated in the upper cast part and the lower cast part is connected to a bottom region (lower region) of the tube. In an alternative configuration, the tube for receiving the bearing bushing (the bushing receptacle) is a separate part. The link elements or link halves are connected to the tube in an upper or a lower region. A further possibility consists in part or a half of the receiving tube for the bearing bushing being introduced or cast into the upper link element, and a second part or a second half into the lower link element. When the two link elements or link halves are connected to each other, the receiving tube or the tubular bushing receptacle is formed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention is described in more detail below with reference to preferred embodiments which are illustrated in the attached schematic drawings, in which: 
           [0020]      FIG. 1  shows a first embodiment of a link assembly according to the invention in a partially disassembled state; 
           [0021]      FIG. 2  shows the link assembly according to  FIG. 1  in a mounted state; 
           [0022]      FIG. 3  shows a second embodiment of a link assembly according to the invention in a partially disassembled state; 
           [0023]      FIG. 4  shows the link assembly according to  FIG. 3  in a mounted state, and 
           [0024]      FIG. 5  shows an axle assembly with two link assemblies arranged on a vehicle axle. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    Elements which are identical or act in an identical manner are identified in all of the figures with the sane reference signs. 
         [0026]      FIGS. 1 and 2  show a first preferred embodiment of a link assembly  10  with a longitudinal link  20  which is formed by an upper link element  30  and a lower link element  40 . The link elements  30 ,  40  can be formed as cast parts and are each of curved design. 
         [0027]    A bushing receptacle  60  for receiving a bearing bushing (not illustrated) is formed at a first end  22  of the upper link element  30 , said bushing receptacle bounding an opening  32  for the bearing bushing with a cylindrical cross section. The bushing receptacle  60  comprises a cylindrical wall  62  with a cylindrical outer surface  64  and a likewise cylindrical inner surface  66 . Link webs  34  extend from the cylindrical outer surface  64  in the direction of a second end  24  of the link element  30  or longitudinal link  20 . The link webs  34  and the cylindrical wall  62  are formed as an integral cast part or welded to each other. At the second end  24 , the upper link element  30  has a recess  36  (cutout, indentation) for receiving a vehicle axle  12 . The vehicle axle  12  is, for example, a cylindrical axle tube. The recess  36  correspondingly preferably has a circular-arc-shaped contour. Furthermore, a receptacle  26  for receiving a damping and/or spring element is formed at the second end  24  of the link assembly  10 . 
         [0028]    The lower link element  40  has an abutment surface  43  at its first end  22  for bearing against the cylindrical outer surface  64  of the bushing receptacle  60 . The in particular circular-arc-shaped abutment surface  43  is adapted to the curvature of the outer surface  64 . A recess  46  (cutout, indentation) for receiving the vehicle axle  12  is formed at the opposite second end  24 . In the joined-together state of the link elements  30 ,  40 , the recesses  36  and  46  form a circumferentially closed opening for the vehicle axle  12 , preferably with a cylindrical cross section. Curved link webs  44  extend between the first end  22  and the second end  24 . 
         [0029]    For the connection of the upper link element  30  to the lower link element  40 , connecting or joining regions  38  and  48  are respectively formed on the upper link element  30  and on the lower link element  40  in the region of the second end  24  along the vehicle axle  12 . The link elements  30 ,  40  are in contact in the region of the connecting regions  38 ,  48  and are preferably connected to each other there in an integrally bonded manner. A second connection of the link elements  30 ,  40  takes place in the region of the first end  22  by means of a preferably integrally bonded connection of the abutment surface  43  to the outer surface  64  of the wall  62  of the bushing receptacle  60 . The link elements  30 ,  40  can thereby be fixedly connected to each other at their opposite longitudinal ends, while a clearance  14  is formed in an inner region between the link elements  30 ,  40  without contact of the link elements  30 ,  40 . 
         [0030]    The bushing receptacle  60  serves for receiving a bearing bushing, preferably a plastic bushing or rubber bushing which can be designed, for example, as what is referred to as a 3D bushing (three-dimensional bushing). The bearing bushing can be designed, for example, according to U.S. Pat. No. 5,690,353, the disclosure of which is included to this extent by reference. The bearing bushing can be mounted on a bearing journal  16  which defines a pivot axis  18 . The link assembly  10  or the longitudinal link  20  is thereby mounted rotatably about the pivot axis  18 . 
         [0031]      FIG. 5  shows a perspective view of an axle unit with two link assembles  10  which are arranged opposite each other or next to each other and substantially correspond to the embodiment according to  FIGS. 1 and 2 . The respective upper link elements  30  face the vehicle, while the lower link elements  40  face the ground or face away from the vehicle. 
         [0032]      FIGS. 3 and 4  show a further embodiment of a link assembly  10  according to the invention. In contrast to the embodiment according to  FIGS. 1 and 2 , the bushing receptacle  60  is designed as a separate part which can be secured in the region of the first end  22  both to the upper link element  30  and to the lower link element  40 . The bushing receptacle  60  has a cylindrical wall  62  with a cylindrical outer surface  64  and a cylindrical inner surface  66 . The upper link element  30  has a curved abutment surface  33  for bearing against the cylindrical outer surface  64  of the sleeve-shaped bushing receptacle  60 . The abutment surface  33  extends as a curved plate with a circular-arc-shaped contour between two link webs  34  which run next to each other and extend in the direction of the second end  24 . 
         [0033]    The lower link element  40  is designed substantially analogously to the upper link element  30 . The link element  40  has a curved abutment surface  43  for bearing against the cylindrical outer surface  64  of the sleeve-shaped bushing receptacle  60 . The abutment surface  43  extends as a curved plate with a circular-arc-shaped contour between two link webs  44  which run next to each other and extend in the direction of the second end  24 . 
       LIST OF REFERENCE SIGNS 
       [0000]    
       
           10  Link assembly 
           12  Vehicle axle 
           14  Clearance 
           16  Bearing journal 
           18  Pivot axis 
           20  Longitudinal link 
           22  First end 
           24  Second end 
           26  Receptacle 
           30  Upper link element 
           32  Opening 
           33  Abutment surface 
           34  Link web 
           36  Recess 
           38  Connection region 
           40  Lower link element 
           43  Abutment surface 
           44  Link web 
           46  Recess 
           48  Connecting region 
           60  Bushing receptacle 
           62  Wall 
           64  Outer surface 
           66  Inner surface

Technology Classification (CPC): 1