Abstract:
A steering knuckle pin bearing assembly includes a bearing and a steering knuckle pin pivotably supporting a steering knuckle relative to an axle beam. A sealing collar seals a space between the bearing and the steering knuckle pin, which space may include a spacer washer. The sealing collar is slidably borne on a radial outer surface of the bearing. In addition, the sealing collar has at least one sealing region that is in slidable contact with an at least substantially cylindrical sealing surface of the axle beam.

Description:
CROSS-REFERENCE 
     The present application claims priority to German patent application no. 10 2008 059 454.7 filed Nov. 28, 2008, the contents of which are incorporated fully herein by reference. 
     TECHNICAL FIELD 
     The present disclosure generally concerns a seal for a steering knuckle pin bearing, which may be utilized, e.g., in motor vehicle applications. 
     RELATED ART 
     A known steering knuckle pivotably supports a steerable wheel of a motor vehicle on an axle beam of the vehicle chassis via a steering knuckle pin, which is inserted into bores in the steering knuckle and/or in the axle beam. Needle roller bearings may also radially support the steering knuckle pin relative to the axle beam. The steering knuckle pin absorbs radial forces. Axial forces are transferred via an axial roller bearing between the steering knuckle and the axle beam and/or the steering knuckle pin. The axial roller bearing may be a tapered roller bearing or a cylindrical roller bearing that is mounted on the steering knuckle pin. 
     One or more spacer- and/or shim washers can be disposed between the axle beam and the axial roller bearing. The thickness of the washer(s) is selected so that the clearance of the axle beam relative to the steering knuckle in the axial direction does not exceed a predetermined maximum amount. In order to avoid corrosion, a gap or space between the axle beam and the axial roller bearing is sealed, in which gap the spacer washer is disposed. Any sealing assembly utilized in this location is preferably designed to be removed and re-installed in a simple manner so that, e.g., the spacer washer can be easily replaced when necessary. 
     Consequently, there is a long-felt need in the art to provide a good-sealing, easily-installable sealing collar for sealing a steering knuckle pin bearing. 
     SUMMARY 
     In one aspect of the present teachings, a steering knuckle pin bearing assembly includes a steering knuckle pin for pivotably bearing a steering knuckle in an axle beam. A sealing collar preferably seals a space or gap between a bearing and the steering knuckle pin. The sealing collar is preferably slidably borne or supported on a radial outer surface of the bearing. 
     In a further aspect of the present teachings, the sealing collar preferably has at least one sealing region that is slidable onto an at least substantially cylindrical sealing surface of the axle beam. The gap between the bearing, which may be embodied, e.g., as an axial roller bearing, and the steering knuckle pin and/or the gap between the axial roller bearing and the axle beam can be reliably sealed thereby. By utilizing such a sealing collar, the installation and removal of the seal, and thus a spacer/shim washer protected thereby, can be achieved in a simple manner. For example, in comparison to known sealing assemblies having labyrinth seals, a better sealing capability and a lower sensitivity to axial tolerances of the components can be achieved. 
     As utilized herein, a “cylindrical sealing surface” includes, among others, substantially cylindrical surfaces that differ from a perfect cylindrical shape by the inclusion of structures such as one or more ribbings, channels and/or grooves. 
     In preferred embodiments, the sealing collar may comprise an elastomeric body having a sealing lip and a reinforcement sleeve made of metal. Such sealing collars provide a good seal and at the same time are also very stable. 
     The present teachings are applicable, e.g., to steering knuckle pin bearings for trucks, which require large axial roller bearings. However, the skilled person will recognize that the present teachings are applicable to a variety of fields, in which a rotating shaft and/or bearing requires a reliable seal or outer covering. 
     In another preferred embodiment, the reinforcement sleeve of the sealing collar may include a radially-extending flange on an end that faces and/or contacts the axle beam. The flange preferably abuts on a radially-extending step of the axle beam in the pushed-on or installed position of the sealing collar. The radially-extending step enables the sealing position of the sealing collar to be reliably fixed or set and/or reliably prevents the sealing collar from being pushed too far onto the axle beam during the installation thereof. 
     If the cylindrical sealing surface of the axle beam has a larger diameter than the radial outer surface of the bearing and/or the sealing collar extends in a stepped, tapered and/or bulged manner, a sufficient space for the radial clearance of a spacer or shim washer can be made possible. 
     In other embodiments, a good seal of the sealing collar on the outer surface of the bearing may be achieved by providing a plurality of sealing lips in different axial positions along the portion of the sealing collar that abuts on the radial outer surface. The sealing lips can be embodied, e.g., as elevations of a corrugated structure. 
     In another aspect of the present teachings, the sealing surface on the axle beam preferably includes at least one at least partially circumferentially-extending groove. In this embodiment, the sealing collar also preferably includes an at least partially circumferentially-extending bead configured to engage in the groove in the pushed-on or installed position of the sealing collar on the axle beam. The sealing properties of the sealing collar can be improved thereby and, at the same time, a latching of the sealing collar in its intended installation position can be achieved by a snap-fit of the bead in the groove. 
     The sealing properties and the retention of the sealing collar on the sealing surface can be further improved, e.g., by providing a ribbed structure on at least one section of the sealing surface. 
     In another aspect of the present teachings, the bearing is preferably an axial roller bearing and the outer shell of the axial roller bearing is preferably formed from a metal sleeve that captively retains the two races of the axial roller bearing prior to the installation. The axial roller bearing having the metal sleeve can, together with the sealing collar, form a pre-assembled subcomponent. 
     A sufficient radial clearance for the shim washer can be achieved, e.g., if the sealing collar includes a smaller diameter first region abutting on the outer surface of the axial roller bearing and a second region having a larger diameter abutting on the axle beam. The second region preferably axially overlaps with the shim washer, which is disposed between the side of the axial roller bearing and the side of the axle beam that face each other in the axial direction of the steering knuckle pin. 
     Further advantages, objects and features of the present teachings will be readily derivable by a skilled person from the following description of the figures and from the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a schematic illustration of a steering knuckle pin bearing having a steering knuckle pin, a steering knuckle and an axle beam. 
         FIG. 2  shows a cut-out section from  FIG. 1  with a detailed illustration of an axial roller bearing and a sealing collar. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Each of the additional features and teachings disclosed below may be utilized separately or in conjunction with other features and teachings to provide improved seals and/or bearing assemblies, as well as methods for designing, constructing and using the same. Representative examples of the present invention, which examples utilize many of these additional features and teachings both separately and in combination, will now be described in further detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Therefore, combinations of features and steps disclosed in the following detail description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the present teachings. 
     Moreover, the various features of the representative examples and the dependent claims may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings. In addition, it is expressly noted that all features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original disclosure, as well as for the purpose of restricting the claimed subject matter independent of the compositions of the features in the embodiments and/or the claims. It is also expressly noted that all value ranges or indications of groups of entities disclose every possible intermediate value or intermediate entity for the purpose of original disclosure, as well as for the purpose of restricting the claimed subject matter. 
       FIG. 1  schematically shows a wheel suspension for a steerable front wheel of a motor vehicle. A steering knuckle  14  is pivotably borne relative to an axle beam  16 . The steering knuckle  14  and the axle beam  16  are pivotably connected with each other via a steering knuckle pin  12 . The steering knuckle pin  12  is rotatably borne or supported in the steering knuckle  14  via a bearing  54  and, if necessary, an additional bearing  56 , which bearings may be, e.g., needle roller bearings. 
     The axle beam  16  is axially supported on a radially-extending step  58  of the steering knuckle  14  via an axial roller bearing  10 . A spacer or shim washer  52  is disposed between the axial roller bearing  10 , which is preferably a tapered roller bearing, and a facing side  48  ( FIG. 2 ) of the axle beam. The shim washer  52  limits the axial clearance of the axle beam  16  relative to the steering knuckle  14  to a minimum. 
     A sealing collar  18  seals or covers a space between the axial roller bearing  10  and the axle beam  16 . The shim washer  52  is also disposed in this space. 
       FIG. 2  shows a cut-out section from  FIG. 1  with the axial roller bearing  10  and the sealing collar  18  in a more detailed view. 
     The axial roller bearing  10  preferably comprises an upper race  40  and a lower race  42 , each of which includes a track, in which tapered roller bodies of the axial roller bearing  10  move. A metal sleeve  38  captively retains the two races  40 ,  42 , so that the axial roller bearing  10  may preferably form a pre-assembled subcomponent. The roller bodies are guided in a bearing cage  60 . The lower race  42  abuts on the radially-extending step  58  of the bore of the steering knuckle  14 . The metal sleeve  38  encompasses the axially-facing side of the upper race  40 . The shim washer  52  abuts on a radially-extending portion of the metal sleeve  38 . When an axial force is transferred via the axial roller bearing  10 , the axially facing side  48  of the axle beam  16  is braced on the shim washer  52 . 
     Three sealing lips  20  of the sealing collar  18 , which together form a wave-shaped or undulating inner side of a first region  44  of the sealing collar  18 , abut on the radial outer surface  19  of the axial roller bearing  10 . Less or more than three sealing lips  20  may be utilized in alternate embodiments. The radial outer surface  19  of the axial roller bearing  10  is the radial outer surface of the metal sleeve  38 . 
     The sealing collar  18  preferably comprises an elastomeric body  26  and a metallic reinforcement sleeve  24 , which may be, e.g., a deep-drawn metal plate part. The entire sealing collar  18  may have a material thickness, e.g., of about 1.5 mm, which may be divided approximately into equal halves between the elastomeric body  26  and the reinforcement sleeve  24 , although other thickness are naturally within the scope of the present teachings. The reinforcement sleeve  24  can form an outer sheathing of the sealing sleeve  18 . The elastomeric body  26  can be vulcanized on the reinforcement sleeve  24 , pressed into the reinforcement sleeve  24  or adhered thereto. 
     The reinforcement sleeve  24  preferably includes a radially-extending flange  28  on an end facing the axle beam  16 . The axial end face of the flange  28  is preferably free from elastomeric material. In the fully pushed-on (i.e. installed) position of the sealing collar  18  illustrated in  FIG. 2 , the top face of the flange  28  abuts on a radially-extending step  30  of the axle beam  16 . 
     The sealing collar  18  has, in a second region  46 , an inner diameter D 2  that is larger than the inner diameter D 1  in the first region  44 . Thus, the sealing collar  18  enlarges in the radial direction between the regions  44 ,  46 , e.g., in a ramp-like, tapered, bulged or step-like manner. In the sealing configuration illustrated in  FIG. 2 , the radial enlargement ends at the height of the axially facing side of the axial roller bearing  10 , so that the other diameter D 2  creates a radial clearance for the shim washer  52 . 
     The steering knuckle pin  12  is inserted into a bore  62  of the axle beam  16 . A substantially cylinder-shaped outer sealing surface  22  is formed on the axle beam  16  concentric to the bore. The sealing surface  22  intended for facing and/or contacting the upper surface of the elastomeric body  26  is formed with a corrugation or other undulating structure  36 . 
     In addition or in the alternative, the sealing surface  22  preferably comprise a relatively deep groove  32  in a region adjacent to the step  30 . In the sealing position of the sealing collar  18  illustrated in  FIG. 2 , a bead  34  of the elastomeric body  26  of the sealing collar  18  engages in the groove  32 . The bead  34  and the groove  32  preferably form a snap-fit connection between the sealing collar  18  and the sealing surface  22  in the sealing configuration. 
     In certain embodiments, the sealing collar  18  and the axial roller bearing  10  may form a pre-assembled subcomponent. 
     In order to install or replace the axial roller bearing  10  and/or the shim washer  52 , the sealing collar  18  may be axially slid in the downward direction with respect to the orientation illustrated in  FIG. 2 , so that the flange  28  withdraws in the axial direction below the top side  50  of the axial roller bearing  10 . After inserting the axial roller bearing  10  and/or shim washer  52 , the sealing collar  18  is pushed/slid upwardly over the sealing surface  22 , wherein the axial roller bearing  10  remains retained on the axle beam  16  in a captive manner, thereby simplifying the installation. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 REFERENCE NUMBER LIST 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 
                 Axial roller bearing 
               
               
                 12 
                 Steering knuckle pin 
               
               
                 14 
                 Steering knuckle 
               
               
                 16 
                 Axle beam 
               
               
                 18 
                 Sealing collar 
               
               
                 19 
                 Outer surface 
               
               
                 20 
                 Sealing lip 
               
               
                 22 
                 Sealing surface 
               
               
                 24 
                 Reinforcement sleeve 
               
               
                 26 
                 Elastomeric body 
               
               
                 28 
                 Flange 
               
               
                 30 
                 Step 
               
               
                 32 
                 Groove 
               
               
                 34 
                 Bead 
               
               
                 36 
                 Corrugation 
               
               
                 38 
                 Sleeve 
               
               
                 40 
                 Race 
               
               
                 42 
                 Race 
               
               
                 44 
                 Region 
               
               
                 46 
                 Region 
               
               
                 48 
                 Facing side 
               
               
                 50 
                 Facing side 
               
               
                 52 
                 Spacer/shim washer 
               
               
                 54 
                 Bearing 
               
               
                 56 
                 Bearing 
               
               
                 58 
                 Step 
               
               
                 60 
                 Bearing cage 
               
               
                 62 
                 Bore 
               
               
                 D1 
                 Diameter 
               
               
                 D2 
                 Diameter