Abstract:
A gasket for a drive axle of a vehicle has an inner periphery defining an aperture and an outer periphery having a first diameter portion and a second diameter portion. The second diameter portion is greater than the first diameter portion. The gasket also has an intermediate portion between the peripheries. The intermediate portion has a plurality of apertures defined therein.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a drive axle hub gasket and a method of using the same. 
       BACKGROUND OF THE INVENTION 
       [0002]    Rear wheel drive vehicles typically have a differential housing, two axle housings, two axles that pass through the axle housings, two wheel hubs, and wheel bearings to support the axle housings on the wheel hubs. Each axle housing is hollow and attached to the differential housing. The axle housings and differential housing are typically a single unitary housing. Tires mounted on rims are conventionally attached to the wheel hubs. A lubricant is contained within the wheel hub to lubricate the bearings. 
         [0003]    It is not uncommon for an axle to be removed from the hub, for example, when the vehicle is towed. Whenever an axle is removed from the hub, the known prior art designs cause the lubricant to be lost. The lubricant must be replaced before the vehicle can be put back in operation. Replacement of the lubricant is often difficult to do efficiently and accurately resulting in high labor costs and significant lost operational time of the vehicle. 
         [0004]    Another disadvantage of the known prior art is that the type of wheel end installed on the vehicle cannot be identified unless at least one axle shaft is removed. 
         [0005]    Examples of prior art devices include U.S. Pat. No. 5,190,355 which teaches a seal ring carrier located between a cap and a hub. A seal member depends from the seal ring carrier. The seal member slidably engages a non-rotating seal journal. The seal ring carrier has a plurality of fastener apertures for receiving the fasteners that secure the cap to the hub. The seal ring carrier separates a bearing grease cavity from an axle lubricant cavity via an inwardly extending radial wall that forms a circular opening to accommodate the journal, the cavity and the drive axle shaft. 
         [0006]    U.S. Pat. No. 5,560,619 describes a gasket that attaches to the outer face of a wheel hub to form a barrier for lubricant. More particularly, the gasket can hold lubricant in place while the axle is reattached to the wheel hub. The gasket can be made of any conventional gasketing material that is relatively thin. Holes are provided to accommodate the bolts of the wheel hub. The gasket includes a solid interior retaining portion below an inner opening. The inner opening has a larger diameter than the outer diameter of the drive shaft. The solid interior retaining portion is only said to be of a predetermined area to partially cover the inner cavity of the wheel hub when the gasket is mounted to the outer face of the wheel hub. An adhesive can be applied to one face of the gasket to help the gasket stick to and seal with the outer face of the wheel hub. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is directed toward a drive axle hub gasket having an inner periphery, an outer periphery and an intermediate portion. The inner periphery defines an aperture. The outer periphery has a first diameter portion and a second diameter portion. The second diameter portion is greater than the first diameter portion. The intermediate portion is located between the peripheries and it has a plurality of apertures defined therein. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which: 
           [0009]      FIG. 1  is an exploded schematic, perspective view of one embodiment of an axle shaft, a wheel hub and a gasket of the present invention; 
           [0010]      FIG. 2  is a schematic, front view of one embodiment of the present invention; 
           [0011]      FIG. 3  is a schematic, side view of the invention depicted in  FIG. 2  as seen along arrows A-A; 
           [0012]      FIG. 4  is a schematic view of the present invention of  FIG. 2  taken along lines B-B; 
           [0013]      FIG. 5  is a schematic, perspective view of another embodiment of the present invention; 
           [0014]      FIG. 6  is a schematic, front view of another embodiment of the present invention; 
           [0015]      FIG. 7  is a schematic, front view of another embodiment of the present invention; 
           [0016]      FIG. 8  is a schematic, front view of another embodiment of the present invention; and 
           [0017]      FIG. 9  is a schematic, front view of another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions, directions or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless the claims expressly state otherwise. 
         [0019]    Referring now to  FIG. 1 , an exploded, schematic view of a wheel hub  20  and an axle shaft  22  for a vehicle (not shown) is depicted. The axle shaft  22  and wheel hub  20  may be part of a floating axle assembly. For the present description, a floating axle assembly is an axle shaft  22  that is removable from the wheel hub  20 . Those skilled in the art appreciate that such an assembly typically includes a differential housing (not shown), an axle housing (not shown), the wheel hub  20 , the axle shaft  22  and wheel bearings  40 . 
         [0020]    The axle shaft  22  is provided with a flange  24  containing a plurality of apertures  26 . The apertures  26  receive threaded bolts  28  located on the wheel hub  20 . The bolts  28  are located through the apertures  26  and a nut  30  is located on each bolt  28  to secure the axle shaft  22  to the wheel hub  20 .  FIG. 1  partially depicts one side of a floating axle assembly. It can be appreciated that a second substantially similar assembly is located on the other side of the differential housing. 
         [0021]    The wheel hub  20  has an axis of rotation  32 , an inner face  34 , an outer face  36  and a cavity  38 . A plurality of bearings  40  and a quantity of lubricant  42  are located within the cavity  38 . The lubricant  42  reduces friction in the bearings  40  and transfers heat from the bearings  40 . 
         [0022]    A gasket  44  is located between the outer face  36  and an inside surface  46  of the axle flange  24  to keep the lubricant  42  from leaking out between the hub  20  and the flange  24 . Referring now to  FIGS. 1-3 , the gasket  44  preferably has a substantially planar inner face  48  and a substantially planer outer face  50 . The gasket  44  also has an inner periphery  52 , an outer periphery  54  and an intermediate portion  56 . The inner periphery  52  defines an aperture  58  substantially centrally located in the gasket  44 . This embodiment of the gasket  44  has an inner peripheral edge  60  with a substantially constant diameter  62 . The intermediate portion  56  is located between the outer periphery  54  and the inner periphery  52  and it contains a plurality of apertures  64 . The apertures  64  receive the bolts  28  from the hub  20 . 
         [0023]    The outer periphery  54  has a first diameter portion  66  and a second diameter portion  68 . Preferably, the second diameter portion  68  is radially larger than the first diameter portion  66 . It is also preferred that the second diameter portion  68  extend along the outer periphery  54  for a predetermined distance to create a tab  70 . 
         [0024]    As seen in the figures, the gasket  44  can comprise two second diameter portions  68  separated by first diameter portions  66 . The second diameter portions  68  are preferably spaced equidistant from one another but they may be located any distance from one another. Further, while the gasket  44  is depicted as having two tabs  70 , it can be appreciated that any number of tabs  70  may be located about the gasket  44  and they may be spaced any distance from one another. 
         [0025]    When the two second diameter portions  68  are spaced equidistant from one another, the gasket  44  is substantially symmetrical about a horizontal x axis  72  and a vertical y axis  74 . It can be appreciated that the plurality of apertures  64  in the intermediate portion  56  are preferably equally spaced from one another and located at substantially equal distances from a center point  76  of the aperture  58  thus making them symmetrical about the x axis  72  and y axis  74  also. 
         [0026]    It can be appreciated that since first and second diameter portions  66 ,  68  are defined, that the outer edges  78 ,  80  of these portions  66 ,  68  are curvilinear. It is within the scope of the present invention, however, for the edges  78 ,  80  to be non-curvilinear. 
         [0027]    Referring now to  FIG. 3 , it can be appreciated that the gasket  44  has a thickness dimension  82  that is much less than the width  84  of the gasket  44 .  FIG. 3  also depicts the substantially planar nature of the inner and outer faces  48 ,  50  of the gasket  44 . 
         [0028]    The gasket  44  may be constructed of a fiber composite material such as that available from Accurate Felt and Gasket Manufacturing Company, Inc. of Cicero, Ill. The fiber composite material is a micropore and hydrofused product currently having product number HFL971. Alternatively, the gasket  44  may be constructed of metal, such as steel, that has been overcoated with a rubber-like material. It is also within the scope of the present invention to form the gasket  44  of paper-like material, as known by those skilled in the art. 
         [0029]    An alternative embodiment of the present invention is depicted in  FIG. 5 . The gasket  44  of  FIG. 5  is substantially similar to the gasket  44  of  FIGS. 1-3 , thus the same reference numbers will be used for like features. The gasket  44  of  FIG. 5 , however, has an inner peripheral edge  86  that varies. More specifically, the inner peripheral edge  86  defines a circular portion  88  around each of the plurality of apertures  64 . It can be appreciated that this embodiment of the gasket  44  utilizes less material that the gasket  44  of  FIGS. 1-3 . It should be appreciated that while the alternative embodiment of  FIG. 5  is depicted with two tabs  70 , as stated before, any number of tabs  70  is within the scope of the present invention and the tabs  70  may be located anywhere along the outer periphery  54 . 
         [0030]    For example,  FIG. 6  depicts another embodiment of the present invention that is substantially similar to the previously discussed and depicted embodiments, thus identical reference numbers are used again. In  FIG. 6 , however, three tabs  70 , equally spaced about the outer periphery  54  of the gasket  44  are depicted. Again, it should be appreciated that it is within the scope of the present invention to locate the tabs  70  at any distance from one another. 
         [0031]      FIG. 7  depicts yet another embodiment of the present invention having just one tab  70 . While the tab  70  is depicted as being located at an upper portion  90  of the gasket  44 , the tab  70  can be located anywhere around the gasket  44 . Furthermore, the tab  70  can comprise any portion of the outer periphery  54  of the gasket  44  and need not be limited to that which is depicted in the figure. The lightweight nature of the tab  70 , or tabs  70  as depicted in the other embodiments, makes locating them anywhere about the outer periphery  54  possible as their impact on the balance of the wheel hub  20  and axle shaft  22  is negligible. 
         [0032]    Another embodiment of the present invention is depicted in  FIG. 8 . While  FIG. 8  depicts a gasket  44  with two tabs  70 , it can be appreciated that any of the above discussed gaskets  44  can be used. The invention depicted in  FIG. 8  differs from the inventions previously discussed in that it defines a dam  92 . While the previously discussed gaskets  44  define wide apertures  58  for the axle shaft  22 , the dam  92  comprises a portion of the inner periphery  52  that extends further inward toward the centerpoint  76  of the gasket  44 . The dam  92  extends inwardly until it touches or almost touches an outer diameter  94  of the axle shaft  22 . For clarity, the portion of the dam  92  that touches or almost touches the axle shaft  22  will be referred to as the inner dam edge  96 . It can be appreciated that a smaller aperture  58  is defined by the gasket  44  of  FIG. 8  for the axle shaft  22  than the apertures  58  of the preceding gaskets  44 . 
         [0033]    The dam  92  is preferably constructed of the same material as the gasket  44 . In a most preferred embodiment, the dam  92  is one-piece and integrally formed with the gasket  44 . It is within the scope of the present invention, however, to separately produce the dam  92  and to produce it from a material different from the rest of the gasket  44 . A dam  92  produced in either of these ways can be attached to the gasket  44  by mechanical-type fasteners, couplings and/or adhesives. 
         [0034]    In the embodiment depicted in  FIG. 8 , the dam  92  has a substantially constant inner dam edge  96  to contact or almost contact the entire circular outer diameter  94  of the axle shaft  22 . The present invention, however, is not limited to dams  92  having only substantially constant diameters. 
         [0035]    For example, as seen in  FIG. 9 , a dam  92  having a substantially triangular aperture  98  is depicted in the gasket  44 . It can be appreciated that the substantially round axle shaft  22  fits through the triangular aperture  98 . The axle shaft  22  may contact one or more of the sides  100  of triangle  98 ; openings at the apexes of the triangle  98  will likely exist. 
         [0036]    While only circular and triangular dams  92  are depicted in the figures, it must be appreciated that the present invention is in no way limited to just these dams  92 . Instead, dams  92  having any number of sides, shapes and dimensions may be used with the present invention. 
         [0037]    Regardless of the dam  92  shape or style, it can be appreciated that the dams  92  provide additional surface area for the gasket  44 . Much like the above discussed tabs  70 , information regarding the gasket  44 , the wheel hub  20  or any other component may be located on the dam  92  of the gasket  44 . 
         [0038]    A method of using the present invention comprises the following steps. It can be appreciated that the present invention has particular utility as a gasket between the outer face  36  and the flange  24  to prevent contaminants from entering the floating axle system or lubricant  42  from leaving the system. 
         [0039]    The invention also has utility in that when the gasket  44  is installed on such a system, the tabs  70  extend outwardly from an outer edge  102  of the flange  24  and from an outer surface  104  of the hub  20 . By extending beyond the flange  24  and the hub  20 , information on the tab  70  or tabs  70  can be easily read by a service person working on any of the above-named components of the vehicle. For example, information regarding the wheel hub type can be located by any means on the tab  70 . By locating the information the tab  70 , one can view it without removing any parts to read it. 
         [0040]    The axle shaft  22  can be removed from the wheel hub  20  and the gasket  44  preferably remains in place on the wheel hub  20 . The gasket  44  can be assured to remain in place on the hub  20  when an adhesive is located on the inner face  48  of the gasket  44  so that it holds to the outer surface  104  of the wheel hub  20 . 
         [0041]    The adhesive may be any product known to those skilled in the art that will not interfere with the performance of the lubricant  42 . One such product may be such as an RTV material, or a room-temperature vulcanizing material. Such materials are traditionally defined as rubber compounds that solidify and stabilize at room temperatures. 
         [0042]    A similar or identical adhesive material  106  may be located, in addition to or separate from the adhesive on the face  48  of the gasket  44 , about the inner peripheral edge  60  of the gasket  44 , as seen in  FIG. 4 . In this location, the material  106  also secures the gasket  44  to the outer surface  104  of the hub  44 . 
         [0043]    When any of the above-described gaskets  44  have any one of the above-described dams  92 , the dam  92  prevents or reduces lubricant  44  from escaping from the wheel hub  20  when the axle shaft  22  is removed. Those skilled in the art appreciate that an axle shaft  22  might be removed from the wheel hub  20  for many reasons including, but not limited to, when the vehicle is to be towed. 
         [0044]    In a preferred embodiment, the inner dam edge  96  of the gasket  44  has a smaller dimension than a diameter  108  of the cavity  38  of the wheel hub  20 . For example, if the gasket  44  having the dam  92  depicted in  FIG. 8  is used, the inner dam edge  96  has a smaller diameter  110  than the diameter  108  of the cavity  38  of the wheel hub  20 . It can be appreciated that the smaller diameter  110  of the inner dam edge  96  prevents lubricant  42  from spilling out of the wheel hub  20  when the axle shaft  22  is removed. Retaining this lubricant  42  within the wheel hub  20  is desirable since it is time consuming and expensive to replace and since it is difficult to replace accurately. 
         [0045]    The dam  92  depicted in the gasket  44  of  FIG. 8 , or any other dam symmetric about a horizontal and a vertical axis  72 ,  74 , permits the axle shaft  22  to be removed at any angular position of the wheel hub  20  or axle shaft  22 . Thus, the wheel hub  20  or the axle shaft  22  need not be rotated to a particular angular orientation for the axle shaft  22  to be removed as the dam  92  will function equally well regardless of the angular orientation of the wheel hub  20 , axle shaft  22  or the dam  92  itself. 
         [0046]    In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiments. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.