Patent Publication Number: US-2011062772-A1

Title: Bearing retainer for heavy-duty vehicle wheel end assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/242,196, which was filed on Sep. 14, 2009. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The invention relates to vehicle wheel end assemblies, and in particular to wheel end assemblies for heavy-duty vehicles, such as tractor-trailers. More particularly, the invention is directed to a bearing retainer for a heavy-duty wheel end assembly, which retains the relative position of the cone of the outboard bearing in a hub during servicing of a brake rotor or components of the wheel end assembly, thereby minimizing potential problems encountered during the disassembly and/or reassembly of the wheel end assembly, and improving the accuracy and efficiency of the servicing operation. 
     2. Background Art 
     For many years, the heavy-duty vehicle industry has utilized wheel end assemblies which are mounted on each end of one or more non-drive axles. Each wheel end assembly typically includes a hub rotatably mounted on a bearing assembly that in turn is immovably mounted on the outboard end of the axle, commonly known as an axle spindle. The bearing assembly includes an inboard bearing and an outboard bearing, which may be separated by a bearing spacer. An axle spindle nut assembly secures the bearing assembly on the axle spindle by threadably engaging threads that are cut into the outer diameter of the outboard end of the axle spindle. In addition to retaining the position of the bearings and any spacer, the axle spindle nut assembly may be used to provide a clamp force to compress the bearings, and any bearing spacer, to a predetermined amount, as will be explained in greater detail below. 
     As is well known to those skilled in the art, for normal operation of the wheel end assembly to occur, the bearing assembly and surrounding components must be lubricated with grease or oil. Therefore, the wheel end assembly also must be sealed to prevent leakage of the lubricant, and also to prevent contaminants from entering the assembly, both of which could be detrimental to its performance. More specifically, a hubcap is mounted on an outboard end of the hub adjacent to and outboard from the axle spindle nut assembly, and a main seal is rotatably mounted on an inboard end of the hub in abutment with the axle spindle, resulting in a closed or sealed wheel end assembly. 
     While most wheel end assemblies include these general features, the design and arrangement of the hub, bearing assembly, any bearing spacer, axle spindle nut assembly, hubcap, main seal, and other components, vary according to the specific vehicle design and its anticipated uses. Moreover, the design and construction of prior art wheel end assemblies exhibit certain disadvantages in properly retaining the relative position of the outboard bearing on the hub during disassembly and/or reassembly of the wheel end assembly. 
     More particularly, as mentioned above, the wheel end assembly is closed or sealed to prevent leakage of lubricant, and to reduce the possibility that contaminants may be introduced into the assembly, as the contaminants may undesirably reduce the life of the bearings and/or other components of the assembly. By way of background, each one of the inboard and outboard bearings includes a cup and a cone, and each cone further includes an integral sub-assembly of multiple rollers, an inner ring that supports the rollers, and a cage which retains the position of each roller on the inner ring. During the initial assembly operation of the wheel end assembly, the cup of the inboard bearing is pressed into the inboard end of the hub, and the cup of the outboard bearing is pressed into the outboard end of the hub. The cone of the inboard bearing then is inserted into the inboard end of the hub, and the main seal is mounted on the inboard end of the hub, which retains the general position of the cone of the inboard bearing. The cone of the outboard bearing is inserted into the outboard end of the hub, and the hub, containing the bearings and main seal, is mounted on the axle spindle. The spindle nut assembly then is installed on the axle spindle to secure the bearing assembly and the hub on the axle spindle. 
     Over the life of the vehicle, it is necessary to service a brake rotor or other components that may be attached to the wheel end assembly, or components of the wheel end assembly itself. During the servicing of such components, the hub of the wheel end assembly must be removed from the axle spindle in a shop environment. In this disassembly operation, the spindle nut assembly is removed from the axle spindle, and a technician then typically pulls the hub, together with the bearings and main seal, as a unit, off of the axle spindle. During the disassembly process, the engagement of the main seal on the inboard end of the hub typically retains the general position of the cone of the inboard bearing. However, in the prior art, once the spindle nut assembly is removed, the cone of the outboard bearing lacks positive mechanical engagement with the outboard end of the hub. 
     As a result, the cone of the outboard bearing may slide out of the outboard end of the hub during the disassembly process. If the outboard bearing slides out of the hub, it may become damaged, and/or the remainder of the wheel end assembly may be exposed to contaminants, either one of which undesirably can reduce the life of the bearings. In addition, if the cone of the outboard bearing slides out of the hub during the disassembly process, or alternatively during reassembly of the wheel end assembly, the outboard end of the hub may undesirably shift or tip radially relative to the axle spindle, which may crimp or kink the main seal on the inboard end of the hub, thereby undesirably causing possible damage to the main seal. 
     Moreover, during reassembly of the wheel end assembly, it is desirable for the outboard bearing cone to be retained in a proper position before the spindle nut assembly is installed onto the axle spindle. More particularly, when the outboard bearing cone is retained in a proper position, the technician is able to focus on installation of the spindle nut assembly onto the axle spindle, rather than on the position of the outboard bearing cone. Such focus on the installation of the spindle nut assembly is important, as the installation of the spindle nut assembly typically is a precise operation. 
     More specifically, installation of the spindle nut assembly onto the axle spindle creates a clamp force on the bearings. For example, when a bearing spacer is employed, tightening of the spindle nut assembly provides a force on the cones of the bearings and the spacer between them, which compresses or pre-loads the bearings. Alternatively, when a bearing spacer is not employed, the position of the spindle nut assembly typically is used to create either a light pre-load on the bearings, or a slight amount of end play to avoid over-compression of the bearings. If the position of the spindle nut assembly does not create a sufficient clamp force on the bearing cones and any spacer, there may be excessive end play of the bearings, which in turn creates excessive axial end play of the wheel end assembly relative to the axle spindle, thereby allowing undesirable movement of the main seal that may reduce the life of the main seal and the bearings. If the position of the spindle nut assembly creates a clamp force on the bearing cones and any spacer that is too high, the bearings may effectively be over-compressed, interfering with their rotation and causing them to possibly wear out prematurely. As a result, optimum positioning of the spindle nut assembly to create an optimum clamp force on the bearing cones and any spacer is important. 
     Therefore, movement of the cone of the outboard bearing out of the hub during disassembly or reassembly of the wheel end assembly may result in contamination of the wheel end assembly, damage to components, and/or potential improper installation of the spindle nut assembly, all of which result in an undesirable increase in the time and cost associated with the servicing of the wheel end assembly. 
     In the prior art, retainers have been employed. However, these retainers typically have been an integral part of a certain type of spindle nut assembly, which is not readily separable from the hub. More particularly, when a brake rotor or components of the wheel end assembly are to be serviced, certain prior art spindle nut assemblies are designed to be loosened on the axle spindle, and then removed from the axle spindle together with the hub. Some of these spindle nut assemblies include retainers, which possess disadvantages associated with reassembly of the wheel end assembly. For example, these retainers allow the cone of the outboard bearing to move somewhat, so that a gap between the bearing cup and cone is created. Because the retainer is part of the spindle nut assembly, during reassembly, the spindle nut assembly prevents a technician from positioning the outboard bearing cone closer to the bearing cup to close the gap between them. Rather, tightening of the spindle nut assembly is used to move the bearing cone toward the bearing cup, which creates the possibility that the outboard bearing cone may be out of position and/or not properly seated when the spindle nut assembly is tightened, thereby binding and thus damaging the bearing. 
     As a result, there is a need in the art for an apparatus that retains the relative position of the outboard bearing, and particularly the cone of the outboard bearing, in a hub during servicing of a brake rotor or of components of the wheel end assembly, thereby minimizing the possibility of contamination of the wheel end assembly, damage to components of the wheel end assembly, and potential improper installation of the spindle nut assembly, all of which improves the accuracy and efficiency of the servicing operation. There is also a need for the bearing retainer to be separate from the spindle nut assembly to provide retention of the relative position of the outboard bearing, and particularly the cone of the outboard bearing, in the hub when the spindle nut assembly is not installed and/or not tightened, and/or to enable a technician to properly position the outboard bearing cone prior to tightening of the spindle nut assembly. The present invention satisfies these needs, as will be described below. 
     BRIEF SUMMARY OF THE INVENTION 
     An objective of the present invention is to provide a bearing retainer for heavy-duty vehicle wheel end assembly that retains the relative position of the outboard bearing, and particularly the cone of the outboard bearing, in a hub during servicing of a brake rotor or of components of the wheel end assembly. 
     Another objective of the present invention is to provide a bearing retainer for heavy-duty vehicle wheel end assembly that minimizes the possibility of contamination of the wheel end assembly, damage to components of the wheel end assembly, and potential improper installation of the spindle nut assembly. 
     Yet another objective of the present invention is to provide a bearing retainer for heavy-duty vehicle wheel end assembly that is separate from the spindle nut assembly to provide retention of the relative position of the outboard bearing, and particularly the cone of the outboard bearing, in the hub when the spindle nut assembly is not installed and/or not tightened. 
     Still another objective of the present invention is to provide a bearing retainer for heavy-duty vehicle wheel end assembly that is separate from the spindle nut assembly to enable a technician to properly position the outboard bearing cone prior to tightening of the spindle nut assembly. 
     These objectives and others are obtained by the bearing retainer for a heavy-duty vehicle wheel end assembly of the present invention. In an exemplary embodiment of the invention, the wheel end assembly includes an inboard tapered roller bearing that is immovably mounted on an axle spindle, an outboard tapered roller bearing that is immovably mounted on the axle spindle outboardly of the inboard bearing, and a wheel hub that is rotatably mounted on the inboard and outboard bearings. The bearing retainer includes a circumferentially-extending groove formed in an inner surface of the wheel hub adjacent an outboard surface of the wheel hub, and a retainer ring that is received in the groove. The retainer ring contacts a radially outward edge of a roller of a cone of the outboard bearing when the roller is at its minimum projected diameter, and the retainer ring is formed with an inner diameter that is larger than an outer diameter of a spindle nut of an axle spindle nut assembly. The retainer ring retains the relative position of the outboard bearing cone in the wheel hub during servicing of components of the wheel end assembly. 
     These objectives and others are also obtained by the method of assembling a heavy-duty vehicle wheel end assembly including a bearing retainer of the present invention. In an exemplary embodiment of the invention, the method includes the steps of providing an inboard tapered roller bearing, providing a wheel hub that includes a circumferentially-extending groove formed in an inner surface of the wheel hub adjacent an outboard surface of the wheel hub, and pressing a cup of the tapered inboard roller bearing into an inboard end of the wheel hub. An outboard tapered roller bearing is provided, and a cup of the tapered outboard roller bearing is pressed into an outboard end of the wheel hub. A cone of the inboard bearing is inserted into the inboard end of the wheel hub, and a cone of the outboard bearing is inserted into the outboard end of the wheel hub. A retainer ring is provided, the retainer ring is compressed to clear the inner surface of the wheel hub, and the retainer ring is inserted into an inner diameter of the wheel hub. The compression of the retainer ring is released when the retainer ring is in alignment with the groove, and the retainer ring seats in the groove, contacting a radially outward edge of a roller of the outboard bearing cone when the roller is at its minimum projected diameter. The wheel hub is mounted on an axle spindle, and the retainer ring retains the relative position of the outboard bearing cone in the wheel hub during servicing of components of the wheel end assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The preferred embodiments of the present invention, illustrative of the best mode in which Applicants have contemplated applying the principles, are set forth in the following description and are shown in the drawings, and are particularly and distinctly pointed out and set forth in the appended claims. 
         FIG. 1  is a fragmentary cross-sectional perspective view of an axle spindle and wheel end assembly of the prior art, shown with a spindle nut assembly and a hubcap installed on the wheel end assembly; 
         FIG. 2  is a fragmentary longitudinal cross-sectional view of the axle spindle and wheel end assembly shown in  FIG. 1 , but without the hubcap on the wheel end assembly; 
         FIG. 3  is a fragmentary cross-sectional view of an axle spindle and wheel end assembly including an exemplary embodiment of the bearing retainer of the present invention, shown with a hubcap and brake rotor installed on the wheel end assembly; 
         FIG. 4  is a reduced-size, exploded perspective view of the wheel end assembly, hubcap and brake rotor shown in  FIG. 3 , but with the axle spindle removed; and 
         FIG. 5  is an enlarged, fragmentary cross-sectional view of a portion of the axle spindle and wheel end assembly shown in  FIG. 3 . 
       Similar numerals refer to similar parts throughout the drawings. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In order to better understand the bearing retainer of the present invention and the environment in which it operates, a prior art axle spindle and wheel end assembly for a heavy-duty vehicle is shown in  FIGS. 1 and 2  and now will be described. An axle  10  depends from and extends transversely across the trailer of a heavy-duty tractor-trailer (not shown). A typical heavy-duty tractor-trailer includes one or more non-drive axles  10  suspended from the trailer, with each of the axles having a wheel end assembly  12  mounted on each end of the axle. Since each of the ends of axle  10  and its associated wheel end assembly  12  are generally identical, only one axle end and wheel end assembly  12  will be described herein. Axle  10  includes a central tube (not shown), and an axle spindle  14  is integrally connected by any suitable means, such as welding, to each end of the central tube. The axle central tube generally is tubular-shaped and is formed with an internal cavity (not shown). Axle spindle  14  is formed with a corresponding internal cavity  16 . 
     Wheel end assembly  12  includes a bearing assembly having an inboard bearing  18  and an outboard bearing  22 . Inboard bearing  18  and outboard bearing  22  are heavy-duty tapered roller bearings. More particularly, inboard bearing  18  includes a cup  19  and a cone  20 , and the cone further includes a plurality of rollers  60 , a race or radially inner ring  62  that supports the rollers, and a cage  63 , which retains the position of each roller on the inner ring. Outboard bearing  22  includes a cup  23  and a cone  24 , and the cone further includes a plurality of rollers  64 , a race or radially inner ring  66  that supports the rollers, and a cage  67 , which retains the position of each roller on the inner ring. Cup  19  of inboard bearing  18  is pressed into an inboard end of a hub  30 . Cone  20  of inboard bearing  18  is mounted on the outer diameter of axle spindle  14  and has its inboard surface in abutment with a shoulder  26  formed in the axle spindle. Cup  23  of outboard bearing  22  is pressed into an outboard end of hub  30 . Cone  24  of outboard bearing  22  is mounted on axle spindle  14  near the outboard end of the axle spindle. A cavity  28  is defined by inboard and outboard bearings  18 ,  22 , axle spindle  14  and hub  30 . A bearing spacer (not shown) optionally is disposed between bearings  18 ,  22  in cavity  28  to conveniently maintain proper spacing between the bearings. 
     Hub  30  is rotatably mounted on inboard and outboard bearings  18 ,  22  in a manner known to those skilled in the art. More particularly, the initial assembly operation for wheel end assembly  12  typically includes pressing inboard bearing cup  19  into the inboard end of hub  30 , and pressing outboard bearing cup  23  into the outboard end of the hub. Inboard bearing cone  20  then is inserted into the inboard end of hub  30 , and a main seal  52  is mounted on the inboard end of the hub. Outboard bearing cone  24  is inserted into the outboard end of hub  30 , and the hub with bearings  18 ,  22  and main seal  52  is mounted on axle spindle  14 . An axle spindle nut assembly  32  is installed on axle spindle  14  to secure bearings  18 ,  22  and hub  30  on the axle spindle. 
     Axle spindle nut assembly  32  includes an optional inner washer  34 , an axle spindle nut  36 , an outer washer  38 , and at least one screw  40 . Axle spindle nut  36 , washers  34 ,  38  and screw  40  cooperate to secure bearings  18 ,  22  and hub  30  in place, and to provide the proper clamp force on bearing cones  20 ,  24  and any spacer. More particularly, nut  36  threadably engages axle spindle  14  and abuts the outboard end of outboard bearing  22  when inner washer  34  is not used. When inner washer  34  is used, nut  36  contacts the inner washer, and the inner washer in turn contacts outboard bearing  22 . Nut  36  receives outer washer  38  in an assembled state, and the outer washer is formed with a tab  42  ( FIG. 4 ) on its inner periphery, which engages a keyway (not shown) formed in axle spindle  14  to prevent the outer washer from rotating once it is installed on the axle spindle. Teeth formed on each one of nut  36  and outer washer  38  enable the nut and washer to positively mechanically engage and interlock with one another, thereby preventing the nut from undesirably rotating after installation on axle spindle  14 . 
     A hubcap  44  is mounted on the outboard end of hub  30  by a plurality of bolts  46  ( FIG. 3 ) that each pass through a respective one of a plurality of openings  48  ( FIG. 3 ) formed in the hubcap, and threadably engage a respective one of a plurality of aligned threaded openings  50  ( FIG. 3 ) formed in the hub. In this manner, hubcap  44  closes the outboard end of wheel end assembly  12 . As described above, main continuous seal  52 , which is rotatably mounted on the inboard end of wheel end assembly  12 , closes the inboard end of the assembly. More particularly, seal  52  is mounted on wheel end assembly  12  in a suitable manner and radially bridges hub  30  and axle spindle  14  to seal cavity  28 . In order to maintain proper lubrication and operation of inboard and outboard bearings  18 ,  22 , a suitable amount of lubricant (not shown) is introduced into cavity  28 . A plurality of interference-fit studs  54  are used to mount a brake drum, tire rim and tire (not shown) on wheel end assembly  12 , and bolts  56  ( FIG. 3 ) are used to mount a brake rotor  58  to hub  30  ( FIG. 3 ). 
     As described above, during servicing of brake rotor  58  or other components that may be attached to wheel end assembly  12 , or servicing of components of the wheel end assembly itself, hub  30  must be removed from axle spindle  14  in a shop environment. The disassembly operation includes removing spindle nut assembly  32  from axle spindle  14 , and pulling hub  30 , together with bearings  18 ,  22  and main seal  52  as a unit, off of the axle spindle. During the disassembly process, outboard bearing cone  24  may slide out of the outboard end of hub  30 , which may result in damage to the outboard bearing cone, and/or exposure of the remainder of wheel end assembly  12  to contaminants, either one of which undesirably reduces the life of bearings  18 ,  22 . In addition, the outboard end of hub  30  may undesirably shift or tip radially relative to axle spindle  14 , which may crimp or kink main seal  52 , thereby potentially damaging the main seal. Moreover, during reassembly of wheel end assembly  12 , it is desirable for outboard bearing cone  24  to be retained in a proper position before spindle nut assembly  32  is installed onto axle spindle  14 , so that the technician is able to focus on proper installation of the spindle nut assembly. 
     Therefore, movement of outboard bearing cone  24  out of the outboard end of hub  30  during disassembly or reassembly of wheel end assembly  12  may result in contamination of the wheel end assembly, damage to components, and/or potential improper installation of spindle nut assembly  32 , all of which result in an undesirable increase in the time and cost associated with the servicing of the wheel end assembly. In addition, retainers of the prior art have been an integral part of certain types of spindle nut assemblies that are designed to be loosened on axle spindle  14  and then removed from the axle spindle together with the hub, which prevents proper positioning of outboard bearing cone  24  before the spindle nut assembly is tightened, thereby potentially binding and damaging the bearing. 
     As a result, there is a need in the art for an apparatus that retains the relative position of outboard bearing  22 , and particularly cone  24  of the outboard bearing, in hub  30  during servicing of brake rotor  58  or of components of wheel end assembly  12 , thereby minimizing the possibility of contamination of the wheel end assembly, damage to components of the wheel end assembly, and potential improper installation of spindle nut assembly  32 , all of which improves the accuracy and efficiency of the servicing operation. There is also a need for the apparatus to be separate from spindle nut assembly  32  to provide retention of the relative position of outboard bearing  22 , and particularly cone  24  of the outboard bearing, in hub  30  when the spindle nut assembly is not installed and/or tightened, and/or to enable a technician to properly position the outboard bearing cone prior to tightening of the spindle nut assembly. The present invention satisfies these needs, as now will be described. 
     Turning now to  FIGS. 3-5 , an exemplary embodiment of the bearing retainer of the present invention is shown and is indicated generally at  70 . Bearing retainer  70  finds application in conjunction with prior art axle  10 , including axle spindle  14 , and in accordance with an important feature of the present invention, is incorporated into a wheel end assembly  72 . Wheel end assembly  72  is improved over prior art wheel end assembly  12 , which lacks a bearing retainer. Wheel end assembly  72  is also improved over prior art wheel end assemblies that include a retainer as a part of an axle spindle nut assembly which is removed from axle spindle  14  together with a hub, as bearing retainer  70  is separate from axle spindle nut assembly  32 , which in turn is separate from a hub, as will be described below. Certain aspects of the general construction and operation of wheel end assembly  72  are similar to prior art wheel end assembly  12  described above. Therefore, for the purposes of clarity and convenience, only the differences between wheel end assembly  72 , which incorporates bearing retainer  70  of the present invention, and prior art wheel end assembly  12  will be described in detail below. 
     Wheel end assembly  72  includes a hub  74 , which is rotatably mounted on inboard bearing  18  and outboard bearing  22  as described above. Hub  74  includes an inner surface  78  adjacent a hub outboard surface  76 . Formed in inner surface  78  proximate outboard surface  76  is a circumferentially-extending groove  80 . More particularly, the location of groove  80  in hub inner surface  78  is outboard of an outboard surface  82  of roller  64  of outboard bearing cone  24 , and inboard of an inboard-most surface  86  of hubcap  44 . This location ensures that a retainer ring  88 , designed to seat in groove  80 , prevents outboard bearing cone  24  from sliding out of hub  74 , as will be described below, while not interfering with the fit or installation of hubcap  44 . 
     Groove  80  may be formed with any sufficient width and depth to securely receive retainer ring  88 . For example, groove  80  preferably is formed with a width of from about 0.020 inches to about 0.250 inches, and most preferably with a width of about 0.074 inches. In addition, groove  80  preferably is formed with a depth of from about 0.020 inches to about 0.250 inches, and most preferably with a depth of about 0.125 inches. 
     Retainer ring  88  is received in and seats in groove  80 , and preferably is a flat, split-type ring. More particularly, ring  88  is formed with a split  90 , so that during assembly of wheel end assembly  72 , an installer can easily compress the ring against its bias to clear inner surface  78  of hub  74  to reach groove  80  from the outboard end of the hub. Once the installer aligns ring  88  with groove  80 , the compression on the ring is released, enabling the ring to expand according to its bias in a radially outward direction so that its outer diameter  92  contacts a corresponding outer diameter surface  94  of the groove, and thus is securely mechanically seated in and engages the groove. For example, once inboard bearing cup  19  is pressed into the inboard end of hub  74 , and outboard bearing cup  23  is pressed into the outboard end of the hub, inboard bearing cone  20  is inserted into the inboard end of the hub, main seal  52  is mounted on the inboard end of the hub, outboard bearing cone  24  is inserted into the outboard end of the hub, and the installer inserts retainer ring  88  into groove  80 . Flub  74  with bearings  18 ,  22 , main seal  52  and retainer ring  88  then is mounted on axle spindle  14 . 
     Retainer ring  88  is formed with an inner diameter  96  of a dimension that is sufficient to ensure that the ring protrudes radially inwardly from groove  80  far enough to contact and retain a radially outward edge  84  of roller  64  of outboard bearing cone  24  when the roller is at its minimum projected diameter. More particularly, inner ring  66  of outboard bearing cone  24  is formed with a tapered contact surface  98  for roller  64 , which includes sufficient contact area for the roller to shift or move slightly based on load conditions. Because contact surface  98  is tapered, when roller  64  shifts or moves on the contact surface, radially outward edge  84  of the roller moves radially inwardly or outwardly, as the case may be. As a result, inner diameter  96  of retainer ring  88  is of a sufficient dimension to contact radially outward edge  84  of roller  64  at its radially inward limit, which is referred to as the minimum projected diameter of the roller. Because roller  64 , inner ring  66  and cage  67  of outboard bearing cone  24  are assembled as an integral unit, it is only necessary for retainer ring  88  to contact radially outward edge  84  of roller  64  at its minimum projected diameter to thereby secure and retain the entire outboard bearing cone. 
     Inner diameter  96  of retainer ring  88  is also larger than the outer diameter of nut  36  and any inner washer  34  ( FIG. 1 ) of axle spindle nut assembly  32 . This structure ensures that retainer ring  88  remains separate from spindle nut assembly  32 , and does not interfere with installation of the spindle nut assembly onto axle spindle  14 . As a result, during reassembly of wheel end assembly  72 , if outboard bearing cone  24  has to be positioned more closely to outboard bearing cup  23 , a technician is able to properly position the outboard bearing cone prior to installation of axle spindle nut assembly, which minimizes the possibility that the bearing cone may bind during tightening of the axle spindle nut assembly. By way of example, retainer ring  88  preferably is formed with an inner diameter  96  of from about 4.435 inches to about 6.000 inches, and most preferably about 5.375 inches. Of course, the size of inner diameter  96  depends on the diameter of outboard bearing  22 . In addition, retainer ring preferably is formed with an outer diameter  92  of about 6.125 inches. 
     In this manner, retainer ring  88  is able to retain the relative position of cone  24  of outboard bearing  22  in hub  30  during servicing of brake rotor  58  or of components of wheel end assembly  12 . As described above, retainer ring  88  is easy to install on hub  74 . The use of retainer ring  88  and of groove  80 , which may be formed in hub  74  during other machining operations for the hub, enables bearing retainer  70  to be simple in construction and cost-effective. Moreover, the split-type construction of retainer ring  88  enables the ring to be easily removable from groove  80  for servicing of bearings  18 ,  22  and/or hub  74 , and to be re-usable. 
     By preventing outboard bearing cone  24  from shifting or moving out of hub  74 , bearing retainer  70  prevents wheel end assembly  72  from being exposed to contaminants during servicing, thereby optimizing the life of bearings  18 ,  22 . In addition, by preventing such movement of outboard bearing cone  24  during disassembly or reassembly of wheel end assembly  72 , bearing retainer  70  reduces the possibility of tipping or shifting of hub  74 , which in turn reduces the possibility of damage to components of the wheel end assembly, such as main seal  52 . The prevention of excessive movement of outboard bearing cone  24  by bearing retainer  70  also enables an installer to focus on proper installation of axle spindle nut assembly  32  to optimize the life of bearings  18 ,  22 , and removes the need for an installer to rebuild or reposition components of wheel end assembly  72 . 
     Furthermore, bearing retainer  70  of the present invention is separate from axle spindle nut assembly  32  and instead is incorporated into hub  74 , in contrast to known retainers of the prior art. By being separate from axle spindle nut assembly  32 , bearing retainer  70  prevents movement of outboard bearing cone  24  when the spindle nut assembly is removed from the axle spindle. In addition, as a discrete component from spindle nut assembly  32 , bearing retainer  70  enables a technician to properly position outboard bearing cone  24  before reinstallation and tightening of the spindle nut assembly after servicing of wheel end assembly  72 , which reduces the possibility that the bearing cone may bind and become damaged when the spindle nut assembly is tightened. 
     As a result, the use of bearing retainer  70  of the present invention desirably minimizes the time and cost associated with the servicing of wheel end assembly  72  and/or components that are attached to the wheel end assembly. 
     The present invention also includes a method for forming a bearing retainer that includes forming a groove in a hub and seating a retainer ring in the groove to prevent excessive movement of the cone of the outboard bearing. The present invention also includes a method for servicing and/or assembling a wheel end assembly and/or components attached to the wheel end assembly using a bearing retainer that includes seating a retainer ring in a groove formed in the hub to prevent excessive movement of the cone of the outboard bearing. Each method includes steps in accordance with the description that is presented above and shown in  FIGS. 3-5 . 
     It is to be understood that other sizes, shapes, forms and configurations for retainer ring  88  may be employed, without affecting the concept or operation of the invention. It is also to be understood that retainer ring  88  may be formed of any suitable material, such as metals, alloys, plastics, elastomers, ceramics, composites, and/or combinations thereof, without affecting the concept or operation of the invention. It is to be further understood that the present invention finds application in all types of axle spindles and wheel end assemblies known to those skilled in the art, including other types of axle spindles and wheel end assemblies than those shown and described herein and known to those skilled in the art, without affecting the concept or operation of the invention. 
     Accordingly, the improved bearing retainer for heavy-duty vehicle wheel end assembly is simplified, provides an effective, safe, inexpensive, and efficient structure which achieves all the enumerated objectives, provides for eliminating difficulties encountered with prior art bearing retainers for heavy-duty vehicle wheel end assemblies, and solves problems and obtains new results in the art. 
     In the foregoing description, certain terms have been used for brevity, clarity and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the present invention has been described with reference to exemplary embodiments. It shall be understood that this illustration is by way of example and not by way of limitation, as the scope of the invention is not limited to the exact details shown or described. Potential modifications and alterations will occur to others upon a reading and understanding of this disclosure, and it is understood that the invention includes all such modifications and alterations and equivalents thereof. 
     Having now described the features, discoveries and principles of the invention, the manner in which the improved bearing retainer for heavy-duty vehicle wheel end assembly is constructed, arranged and used, the characteristics of the construction and arrangement, and the advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations are set forth in the appended claims.