Abstract:
A removable grease dam tool to facilitate proper filling of grease within a wheel hub assembly and a method of using the same. A grease dam is placed adjacent an outer surface of a wheel hub mounted to a spindle. The grease dam blocks at least 50% of the exposed area between the wheel hub and spindle and leaves a top portion open to allow greased to be injected into the inner cavity of the wheel hub. A portion of the grease dam is disposed within the wheel hub between the wheel hub and spindle to simulate the presence of the outer bearing. Once the inner cavity of the wheel hub is filled beyond a 50% fill level, the grease dam is removed and the outer bearing assembly is immediately thereafter installed. The tool prevents leakage of grease during assembly to ensure at least a 50% fill level. A handle is provided to facilitate manipulation by a user.

Description:
[0001]    1. Field of the Invention  
           [0002]    The present invention relates to a tool for greasing wheel bearings and more particularly to a grease dam for ensuring proper fill of grease within the hub cavity prior to installing the outer bearing.  
           [0003]    2. Description of the Prior Art  
           [0004]    Greasing a wheel hub assembly is well known in the art. Heretofore, it has been the practice to first pack the inner bearing with grease and position the inner bearing within the hub and mount the hub and inner bearing upon the spindle. Grease is spread by hand uniformly about the grease cavity within the hub which is manually positioned in alignment on the spindle to receive the grease uniformly prior to mounting the outer bearing. Once grease is installed within the grease cavity the outer bearings are installed and secured to the spindle. The nut assembly and hub cap are then secured. However, because the consistency of the grease is much like molasses, it is impossible to fill the hub cavity more than  30 %, as much of the grease will simply leak out of the end of the hub assembly prior to installing the outer bearing and hub cap. Such insufficient filling of grease within the hub cavity results in premature bearing failure due to a lack of lubrication. Current standards call for filling the hub cavity with grease to at least 50% of the cavity volume. The present invention provides a simple tool for proper filling of grease during assembly of the wheel hub/spindle assembly without the need for complicated wheel end arrangements or greasing tool devices.  
         SUMARRY OF THE INVENTION  
         [0005]    It is an object of the invention to provide a tool for properly filling a wheel hub cavity with grease as well as a method for its use that is superior to the prior art.  
           [0006]    The present invention is directed to a removable grease dam tool to facilitate proper filling of grease within a wheel hub assembly. A grease dam is placed adjacent an outer surface of a wheel hub that is rotatably mounted to a spindle. The grease dam blocks at least 50% of the exposed area between the wheel hub and spindle and leaves a top portion open to allow grease to be injected into the inner cavity of the wheel hub. A portion of the grease dam is disposed within the wheel hub between the wheel hub and spindle to simulate the presence of the outer bearing assembly. Once the inner cavity of the wheel hub is filled with grease beyond a 50% fill level, the grease dam is removed and the outer bearing assembly is immediately thereafter installed. The tool prevents leakage of grease during assembly to ensure at least a 50% fill level. A handle is provided to facilitate manipulation by a user. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a perspective view of the grease dam tool according to the present invention.  
         [0008]    [0008]FIG. 2 is a top plan view of the grease dam tool of FIG. 1.  
         [0009]    [0009]FIG. 3 is a top plan view of the grease dam tool according to an alternate embodiment of the present invention.  
         [0010]    [0010]FIG. 4 is a cross section view of a partially assembled wheel hub spindle assembly.  
         [0011]    [0011]FIG. 5 is a cross sectional view of the partially assembled wheel hub/spindle assembly of FIG. 4 utilizing the grease dam tool of the present invention.  
         [0012]    [0012]FIG. 6 is a front view of a partially assembled wheel hub/spindle assembly.  
         [0013]    [0013]FIG. 7 is a front view of the partially assembled wheel hub/spindle assembly of FIG. 6 with a mounted grease dam of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]    [0014]FIG. 1 depicts a perspective view of the grease dam tool  1  of the present invention to ensure proper grease fill of a wheel hub assembly. The tool  1  is rather simple in construction and its use in the wheel hub assembly ensures at least a 50% grease fill of the wheel hub inner cavity. The grease dam tool  1  has three primary parts. A main portion  3  is formed of a semi-disc shaped substantially planar member having a central semicircular notch  6  to accommodate and engage a spindle. The main portion  3  does not completely circumscribe the central notch  6  but preferably circumscribes the central notch  6  more than 180°. Such an arrangement provides the ability to fill the inner cavity more the 50%. A dam portion  8  extends from the main portion and is shaped to engage the inner surface of a wheel hub and an outer peripheral surface of a spindle. Preferably the dam portion is semi-frustoconically shaped and extends orthoganally from the main portion  6 . The dam portion  8  has a recess  10  to accommodate and engage a wheel spindle. The semi-frustoconical shape of the dam portion  8  and the recess  10  allow the dam portion to be positioned between the wheel hub and the spindle thereby blocking egress of grease as will be later discussed in more detail. A handle  12  is provided to allow the tool to be manipulated by a user. The handle  12  simply extends from the main portion from an opposite side from which the dam portion  8  is provided.  
         [0015]    As can be seen from FIG. 2, the main portion  6 , and the dam portion  8  are secured together by screws  14  which extend through the main portion  6  and engage the dam portion  8  to form an integral body. Other means to secure the main portion  6  and dam portion  8  may be employed such as by adhesive or other commonly known securing means. While it is preferred to form the main portion  6  and dam portion  8  of two separate pieces of plastic, they may be formed of a homogeneously formed single piece of plastic. As further depicted in FIG. 2, a pair of pegs  16  extend from the main portion  6  parallel to and adjacent the dam portion  8 . As will be later described in more detail, the pegs  16  are provided to engage bores formed in an outer face of the wheel hub to properly position and align the grease dam during use.  
         [0016]    [0016]FIG. 3 depicts an alternative embodiment of the present invention. The recess  10   a  formed in the dam portion is stepped to accommodate a different spindle end arrangement.  
         [0017]    [0017]FIG. 4 depicts a partial section view of a conventional partially assembled wheel hub/spindle assembly. An inner bearing assembly  20  is packed with grease and pre-assembled to the wheel hub  22  as is conventionally known in the art. The wheel hub  22  and inner bearing assembly  20  are mounted to the spindle  24  which has be pre-coated with grease. As can be seen, the outer end  25  of the wheel hub/spindle assembly remains open. When grease is inserted into the inner cavity  23  of the wheel hub  22 , once the level reaches the inward most point of the wheel hub, the grease will simply leak out of the open end of  25  of the wheel hub/spindle assembly. Such an arrangement will not allow sufficient filling the hub cavity  23  with lubricating grease.  
         [0018]    [0018]FIG. 5 depicts the same wheel hub arrangement of FIG. 4 with the application of the grease dam tool  1  of the present invention. As can be seen form FIG. 5, the grease dam tool  1  is installed on the outer end  25  of the wheel hub/spindle assembly. The main portion  6  is flush mounted to an outer face  26  of the wheel hub  22  and the dam portion  8  is inserted within the inner cavity  23  between the wheel hub  22  and the spindle  24 . This arrangement blocks the lower portion of the open end  25  of the wheel hub/spindle assembly. In essence the grease dam tool simulates the presence of an outer bearing assembly and blocks the egress of grease from the inner cavity  23 . A grease applicator  33  may then simply inject grease within the inner cavity  23 . Because the grease dam  1  blocks the open end  25 , the grease level may be filled up to the level of the grease dam tool. As previously discussed, the grease dam tool preferably circumscribes the spindle more than 180° and therefore blocks more than 50% of the exposed open end area. Consequently, a grease fill level of at least 50% is achieved. Note the grease level  30  that is located above the center line  31  of the spindle  24  and wheel hub  22 . Once the inner cavity  23  has been sufficiently filled with lubricating grease (at least 50%) the grease dam  1  may be removed and a pre-packed outer bearing assembly immediately installed between the wheel hub  22  and spindle  24  adjacent the outer face  26 . A securing nut may then be secured to the end of the spindle and end play of the wheel hub assembly set as conventionally known in the art.  
         [0019]    [0019]FIG. 6 depicts a front view of the assembly of FIG. 4. AS can bee seen there is an annular space  28  (corresponding to inner cavity  23 ) is disposed between the spindle  24  and the inner surface of the wheel hub  22 . A plurality of lugs nuts  29  are provided on the outer periphery of the hub  22  for securing a wheel thereto. Also, provided are a plurality of bores  27  formed on the outer race  26  which are preferably threaded to receive securing bolts from a hub cap that will seal the entire inner cavity of the wheel hub  22  once filled with grease and fully assembled with the outer bearing assembly etc. As clearly seen the lower portion of the annular space  28  remains open at the end of the wheel hub assembly. Therefore, if grease were simply injected, it would simply leak out prior to achieving a sufficient fill level. FIG. 7 shows a front view of the assembly of FIG. 6 with the application of the grease dam  1  of the present invention. As clearly shown the grease dam  1  blocks the lower portion of the open end  25  of the wheel hub/spindle assembly. The pegs  16  are inserted into corresponding bores  27  to properly position and align the grease dam tool relative to the hub  22 . The engagement of the pegs  16  and bores  27  also serve to help maintain the contact with the outer face  26  of the wheel hub  22  during greasing. A user simply manipulates the handle  12  to align the pegs  16  with the corresponding bores  27  and applies pressure to maintain the main portion  6  flush against the outer face  26 . As previously discussed, lubricating grease is simply then inserted in the exposed portion of the annular space  28  adjacent the top portion of the wheel hub  28 . Once a proper grease fill level is achieved, the grease dam is removed and an outer bearing assembly is immediately installed and the securing nut threaded onto the spindle  24  and end play adjusted. The hub cap is then installed to seal the inner cavity  23  and ensure retainment of the grease within the inner cavity  23 .  
         [0020]    While the foregoing description of the grease dam  1  and its use has been described, the specific method of assembling and lubricating of the wheel hub/spindle assembly will now be described with appropriate reference to the drawings.  
         [0021]    First, an outer bearing assembly is packed with lubricating grease and is preferably packed with Mobil SHC=007 synthetic grease for ready installation in the wheel hub/spindle assembly. A wheel hub  22  is provided with a pre assembled pre-packed inner bearing assembly  20  as in known in the art. Or the inner bearing assembly  20  is packed with grease, as is the outer bearing assembly, and then mounted to the wheel hub  22 . The spindle  24  is then liberally coated with Mobil SHC-007 grease. The wheel hub  22  and inner bearing assembly  20  are then together installed onto the spindle  24 . The grease dam tool  1  is then aligned and positioned relative to the spindle  24  and wheel hub  22  by aligning the pegs  16  with the appropriate bore  27 . As can be seen in the drawing figures, the dam  8  portion is disposed between the wheel hub  22  and spindle  24 , and the main portion  6  is preferably flush mounted with the outer face  26  of the wheel hub  22  so as to block the lower most portion of the open end  25  of the wheel hub/spindle assembly. Pressure is applied to the handle  12  to maintian the grease dam  1  in position. A grease applicator is the used to fill the inner cavity  23  with grease to at least 50%. The cavity being defined by the space between the inner bearing assembly  20 , wheel hub  22 , spindle  24  and dam portion  8  of the grease dam tool  1 . Once the inner cavity  23  is filled to at least 50%, the grease dam tool  1  is removed and the outer bearing assembly is immediately installed between the wheel hub  22  and spindle  24 . The securing nut is then applied and end play adjusted. An additional coating of grease is then applied to the outer surface of the outer bearing assembly and nut assembly. A hub cap is then installed to the outer face  26  of the wheel hub  22  as is known in the art taking care not to cover a vent hole in the hub cap.  
         [0022]    While the foregoing invention has been shown and described with reference to a preferred embodiment, it will be understood by those possessing skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. For example while a specific configuration and shapes has been shown and described for the inner surface of the wheel hub  22  and outer surface of the spindle  24  and the corresponding inner and outer bearing race seats as well as the relative positions of the recited components, the grease dam  1  of the present invention can be so dimensioned to accommodate different wheel hub  22  and spindle  24  configurations so long as the grease dam is capable of blocking the lower portion of the exposed area of the assembly while allowing injection of grease within the inner cavity  23 . It is recognized that different profiles are used in the art to define the inner surface of the wheel hub  22  that defines the shape of the inner cavity  23  and the bearing race seats. Use of the present invention for different spindle profiles and end nut assemblies are also contemplated.