Abstract:
A wheel assembly includes a spindle; a wheel hub rotatable relative to the spindle; a seal mounted between the spindle and the wheel hub, the spindle, the wheel hub, and the seal defining a sealed cavity; and at least one bearing mounted between the spindle and the wheel hub within the sealed cavity, the at least one bearing facilitating rotation of the wheel hub relative to the spindle.

Description:
TECHNICAL FIELD 
     The current disclosure relates to wheel assemblies. Particularly, the current disclosure relates to wheel assembly seals. 
     BACKGROUND 
     Vehicles, including haul trucks such as the Komatsu 930E haul truck, have wheel assemblies that may include a wheel hub mounted on a spindle. A roller bearing may be mounted between the wheel hub and spindle to facilitate rotation of the wheel hub relative to the spindle. The roller bearing may be oiled allow for smooth rotation of the bearings of the roller bearing. 
     SUMMARY 
     Disclosed is a wheel assembly including a spindle; a wheel hub rotatable relative to the spindle; a seal mounted between the spindle and the wheel hub, the spindle, the wheel hub, and the seal defining a sealed cavity; and at least one bearing mounted between the spindle and the wheel hub within the sealed cavity, the at least one bearing facilitating rotation of the wheel hub relative to the spindle. 
     Also disclosed is a method of forming a sealed cavity in a wheel assembly, the wheel assembly including a wheel hub, a spindle, and at least one bearing, the wheel hub rotatable relative to the spindle, the method including mounting a seal between the wheel hub and the spindle; creating a sealed cavity between the wheel hub and the spindle with the seal, the at least one bearing mounted within the sealed cavity; and injecting bearing oil into the sealed cavity. 
     Various implementations described in the present disclosure may include additional systems, methods, features, and advantages, which may not necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure. Corresponding features and components throughout the figures may be designated by matching reference characters for the sake of consistency and clarity. 
         FIG. 1  is a perspective view of a wheel assembly in accord with embodiments of the current disclosure. 
         FIG. 2  is a cross-sectional view of the wheel assembly of  FIG. 1  taken along line  2 - 2 . 
         FIG. 3  is a perspective view of a wheel assembly in accord with embodiments of the current disclosure. 
         FIG. 4  is a cross-sectional view of the wheel assembly of  FIG. 3  taken along line  4 - 4 . 
         FIG. 5  is a perspective view of a wheel assembly in accord with embodiments of the current disclosure. 
         FIG. 6  is a back view of a wheel hub of a wheel assembly in accord with embodiments of the current disclosure. 
         FIG. 7  is a cross-sectional view of the wheel hub of  FIG. 6  taken along line  7 - 7 . 
         FIG. 8  is a front view of a spindle of a wheel assembly in accord with embodiments of the current disclosure. 
         FIG. 9  is a cross-sectional view of the spindle of  FIG. 8  taken along line  9 - 9 . 
         FIG. 10  is a detail cross-sectional view of a mounting flange of the spindle of  FIG. 8  taken from detail  10  shown in  FIG. 9 . 
         FIG. 11  is a front view of a cover of the wheel assembly in accord with embodiments of the current disclosure. 
         FIG. 12  is a cross-sectional view of the cover of  FIG. 11  taken along line  12 - 12 . 
         FIG. 13  is a front view of a seal retainer of a wheel assembly in accord with embodiments of the current disclosure. 
         FIG. 14  is a cross-sectional view of the seal retainer of  FIG. 13  taken along line  14 - 14 . 
         FIG. 15  is a detail cross-sectional view of the wheel assembly of  FIG. 4  taken from detail  15  shown in  FIG. 4 . 
         FIG. 16  is a detail cross-sectional view of a seal of the wheel assembly of  FIG. 4  taken from detail  16  shown in  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed is a wheel assembly seal and associated methods, systems, devices, and various apparatus. The wheel assembly includes a wheel hub, a spindle, and the seal between the wheel hub and the spindle. It would be understood by one of skill in the art that the disclosed wheel assembly seal is described in but a few exemplary embodiments among many. No particular terminology or description should be considered limiting on the disclosure or the scope of any claims issuing therefrom. 
     One embodiment of a wheel assembly  100  is disclosed and described in  FIG. 1 . The wheel assembly  100  is the front wheel assembly of a Komatsu 930E haul truck, though various wheel assemblies of various vehicles, including other haul trucks, may be present in various embodiments. The wheel assembly  100  may be mounted on a suspension cylinder  110 . The wheel assembly  100  includes a wheel hub  120 , a spindle  130 , a cover  140 , and a brake assembly  150 . A wheel flange  124  of the wheel hub  120  is provided with a plurality of bolts  122  extending therethrough for bolting a tire to the wheel hub  120 . The wheel hub  120  is rotatably mounted on the spindle  130  and the brake assembly  150  is coupled to both the wheel hub  120  and the spindle  130 . The cover  140  is fastened to the wheel hub  120  by a plurality of bolts  142 . The suspension cylinder  110  extends through a mounting bore  132  of the spindle  130 . 
       FIG. 2  shows a cross-section of the wheel assembly  100  taken along line  2 - 2  prior to any modification of the wheel assembly  100 . As shown in  FIG. 2 , an axial direction  200  extends through the axis of the spindle  130 , and a radial direction  205  extends transverse to the axial direction  200 . The axial direction  200  extends inwardly from an outer end  232  of the spindle  130 , the outer end  232  of the spindle  130  facing outward from wheel assembly  100  away from the vehicle that the wheel assembly  100  is installed on. The spindle  130  includes a wheel hub attachment portion  230  sized to be inserted into the wheel hub  120 . The wheel hub  120  is mounted around the wheel hub attachment portion  230  on a pair of roller bearings  210   a,b . Roller bearings  210   a,b  are tapered roller bearings, such as tapered roller bearings sold by The Timken Company, though other types of bearings may be used in various embodiments. Each roller bearing  210   a,b  includes a plurality of cylindrical rollers  212   a,b  held between an inner ring  214   a,b  and an outer ring  216   a,b , respectively. The outer rings  216   a,b  may rotate relative to inner rings  214   a,b , respectively. The outer rings  216   a,b  are engaged with the wheel hub  120  and the inner rings  214   a,b  are engaged with the spindle  130 , thereby allowing the wheel hub  120  to rotate relative to the spindle  130 . 
     The roller bearing  210   b  is held in place on the wheel hub attachment portion  230  of the spindle  130  by a bearing spacer  220  and by an inner retaining shoulder  222  formed in an inner end  228  of the wheel hub  120 . The roller bearing  210   a  is held in place by a bearing retainer  250  and by an outer retaining shoulder  224  formed in an outer end  240  of the wheel hub  120 . The bearing retainer  250  is coupled to the outer end  232  of the spindle  130  by a plurality of bolts  252  extending through the bearing retainer  250 , though the bearing retainer  250  may be coupled to the spindle  130  by any method in various embodiments, including welding, gluing, or being formed integrally with the spindle  130 . 
     The bearing retainer  250  also retains the wheel hub  120  on the spindle  130 . The spindle  130  includes a mounting flange  260  formed in the spindle  130  adjacent to the wheel hub attachment portion  230 . The bearing spacer  220  abuts the mounting flange  260  when the roller bearing  210   b  is in position on the wheel hub attachment portion  230 . The bearing retainer  250  and the mounting flange  260  thereby indirectly retain the wheel hub  120  in place about the wheel hub attachment portion  230 , with the bearing retainer  250  retaining the roller bearing  210   a  against the outer retaining shoulder  224  and the mounting flange  260  retaining the bearing spacer  220  and the roller bearing  210   b  against the inner retaining shoulder  222 . However, in various embodiments, the wheel hub  120  may be mounted on the spindle  130  by other methods, and the disclosure of the bearing retainer  250  and the mounting flange  260  should not be considered limiting. 
     The brake assembly  150  is coupled both to the wheel hub  120  and to the spindle  130 . In the current embodiment, the brake assembly  150  is indirectly coupled to the spindle  130  by a brake adapter  270  coupled to the mounting flange  260 . The brake assembly  150  is a wet disc brake assembly, though other brake assemblies may be used in various embodiments. The brake assembly  150  includes a plurality of friction discs  254  and a plurality of separator plates  256  within a piston housing  258 . A separator plate  256  is placed between each friction disc  254 . In the current embodiment, there are ten friction discs  254  and nine separator plates  256 , though other numbers of friction discs  254  and separator plates  256  may be present in various embodiments, and the number of friction discs  254  and separator plates  256  should not be considered limiting. A pair of dampers  282   a,b  are placed on either side of the plurality of friction discs  254  and the plurality of separator plates  256 . The brake assembly  150  also includes a ring gear  284  and an inner gear  286 . The ring gear  284  is coupled to the spindle  130  through the piston housing  258  and the brake adapter  270 , and the inner gear  286  is coupled to the wheel hub  120 , so that the inner gear  286  rotates relative to the ring gear  284  as the wheel hub  120  rotates relative to the spindle  130 . The ring gear  284  is internally splined to retain the dampers  282   a,b  and the separator plates  256 , and the inner gear  286  is splined to retain the friction discs  254 . The friction discs  254  therefore rotate with the inner gear  286  relative to the ring gear  284  and thereby rotate relative to the separator plates  256  and the dampers  282   a,b.    
     A hydraulic piston  280  is mounted in the piston housing  258  and is movable to apply or remove compressive force to the damper  282   b , and thereby the separator plates  256 , the friction discs  254 , and the damper  282   a . When the piston  280  is forced against the damper  282   b , the piston  280  forces the friction discs  254  against the dampers  282   a,b  and the separator plates  256 , thereby slowing and stopping rotation of the friction discs  254 , and thereby the inner gear  286  and the wheel hub  120 , relative to the separator plates  256 , the dampers  282   a,b , the ring gear  284 , and the spindle  130 , braking the wheel hub  120  relative to the spindle  130 . 
     In the current embodiment, due to heat generated by the friction between the friction discs  254 , the separator plates  256 , the dampers  282   a,b , and the piston  280 , the brake assembly  150  is a heat-generating device and cooling the brake assembly  150  with hydraulic oil is required to protect the integrity of all components of the brake assembly  150 . Cooled hydraulic oil is pumped from a hoist cylinder system of the vehicle through a series of priority valves and an oil cooling radiator to an upper portion  290  of the brake assembly  150 , where it flows by gravity into the space between the wheel hub  120  and the spindle  130 . Prior to modification of the wheel assembly  100 , the hydraulic oil may flow through the roller bearings  210   a,b , providing lubrication for the roller bearings  210   a,b . The wheel hub  120  also includes a pair of notched divider flanges  226   a,b  extending radially inward adjacent to the the outer retaining shoulder  224  and the inner retaining shoulder  222 , respectively. The notched divider flanges  226   a,b  are notched to allow oil to flow throughout the space between the wheel hub  120  and the spindle  130  and into the roller bearings  210   a,b . The bearing retainer  250  prevents hydraulic oil from entering the interior of the spindle  130 , and the cover  140  prevents hydraulic oil from exiting the space between the wheel hub  120  and the spindle  130 . The hydraulic oil may flow around the wheel hub attachment portion  230  and down to a lower portion  292  of the brake assembly  150 , where it is pumped back to a main hydraulic tank (not shown) of the vehicle and back to the upper portion  290  to cycle the hydraulic oil back through the brake assembly  150  and the space between the wheel hub  120  and the spindle  130 . A plurality of cooling ports  294  are defined in the inner gear  286  and spaced around the circumference of the inner gear  286  to allow for flow of hydraulic oil in and around the friction discs  254 , the separator plates  256 , the dampers  282   a,b , and the piston  280 . 
     However, while the hydraulic oil is used both to cool and lubricate the brake assembly  150  and to lubricate and cool the roller bearings  210   a,b , the hydraulic oil is specifically designed for use in the brake assembly  150 . Thus the hydraulic oil may not be the best oil for lubrication and cooling of the roller bearings  210   a,b . Heat from the brake assembly  150  or other heat-generating devices may heat the hydraulic oil and lower the viscosity of the oil, adding to wear on the roller bearings  210   a,b , or the hydraulic oil may be contaminated from the brake assembly  150  or other systems of the vehicle, carrying the contaminates into the roller bearings  210   a,b . It may be desirable to use separate oils for the brake assembly  150  and for the roller bearings  210   a,b . Therefore it may be desirable to modify the wheel assembly  100  such that a bearing oil may be used around the roller bearings  210   a,b  and the hydraulic oil may be used in the brake assembly  150 . In various embodiments, the bearing oil may have a viscosity near or above 100 Saybolt Seconds (20 Centistokes) at 212 degrees Fahrenheit (100 degrees Celsius), such as 80W-90 oil, though other oils of different viscosities may be used as bearing oil in various embodiments. It may also be desirable to provide rare earth magnets within the bearing oil to collect metallic contaminates that may be generated by or introduced into the system. 
       FIG. 3  shows a modified wheel assembly  300  without any bolts connecting the components of modified wheel assembly  300 . The wheel assembly  300  includes the brake assembly  150 . The wheel assembly  300  also includes a modified wheel hub  320  and a modified spindle  330 , which are modified over the wheel hub  120  and the spindle  130  as described below.  FIG. 4  shows a cross-sectional view of the wheel assembly  300  taken along lines  4 - 4  as shown in  FIG. 3 . As shown in  FIG. 4 , the wheel assembly  300  also includes the roller bearings  210   a,b , the bearing spacer  220 , the bearing retainer  250 , and a modified cover  440 . The modified cover  440  is modified over the cover  140  as described below. Further, the wheel assembly  300  includes a seal  410  between the wheel hub  320  and the spindle  330 . In the current embodiment, the seal  410  is located between a mounting flange  360  of the spindle  330  and an inner end  428  of the wheel hub  120 , though in various embodiments the seal  410  may be located in various locations between the spindle  330  and the wheel hub  320 . 
     In combination with the wheel hub  320 , the spindle  330 , the bearing retainer  250 , and the cover  440 , the seal  410  forms a sealed cavity  420  between the wheel hub  320  and the spindle  330 . In various embodiments, the cover  440  and/or the bearing retainer  250  may be part of the sealed cavity  420 . The sealed cavity  420  contains the roller bearings  210   a,b  and isolates the roller bearings  210   a,b  from the brake assembly  150 . The sealed cavity  420  may therefore be filled with bearing oil. A pair of notched divider flanges  426   a,b  similar to notched divider flanges  226   a,b  are also located within the sealed cavity  420  in the current embodiment. The wheel hub  320  may also include a plurality of radial holes  470  extending radially through the wheel hub  320 . In the current embodiment, wheel hub  320  includes eight radial holes  470  spaced around the wheel hub  320 , though any number of radial holes  470  may be present in various embodiments. Radial holes  470  may be plugged to seal sealed cavity  420 , and may be drilled as necessary to increase the radius of radial holes  470  to fit plugs. 
       FIG. 5  shows a perspective view of the wheel assembly  300  with the brake assembly  150  removed. As shown in  FIG. 5 , the seal  410  extends completely around the circumference of the wheel hub  320  and the spindle  330  between the inner end  428  of the wheel hub  320  and the mounting flange  360  of the spindle  330 . Wheel hub  320  also includes an axially-extending drainage port  520  extending to sealed cavity  420  at a radially-outermost edge of the sealed cavity  420 . The drainage port  520  is pluggable to seal sealed cavity  420 . 
       FIG. 5  also shows the cover  440  including a check valve  540 . In the current embodiment, the check valve  540  is located in the cover  440 , though the check valve  540  may be located in various locations in the wheel assembly  300  in various embodiments. The check valve  540 , in the current embodiment, is a bolt with a bore defined therethrough and a spring and ball located in the bore. The spring biases the ball against a seat defined in the bore proximate to an end of the check valve  540  facing inward into the sealed cavity  420 . When pressure within the sealed cavity  420  forces the ball against the spring away from the seat, pressure within the sealed cavity  420  is relieved through the check valve  540  to lower pressure within the sealed cavity  420  until the spring forces the ball back against the seat. Air pressure may build within the sealed cavity  420  due heat generated during operation of the wheel assembly  300 , and the check valve  540  allows the excess air pressure to be relieved from the sealed cavity  420 , functioning as a check safety valve. 
       FIG. 6  shows a back view of the wheel hub  320 . As shown in  FIG. 6 , the inner end  428  of the wheel hub  320  includes a plurality of bolt holes  624  for mounting of the seal  410  on the inner end  428 . The inner end  428  also includes a pair of dowel holes  622   a,b  for insertion of dowel pins to align the seal  410  on the inner end  428 . The plurality of bolt holes  624  and the pair of dowel holes  622   a,b  are modifications added to the wheel hub  120  to create wheel hub  320 .  FIG. 6  also shows wheel flange  324  including a plurality of bolt holes  326  sized to accept the plurality of bolts  122  for bolting a tire to the wheel hub  320 .  FIG. 6  also shows a plurality of bolt holes  628  for mounting the brake assembly  150  on the wheel hub  320 . Any number of dowel holes  622 , bolt holes  624 , bolt holes  326 , or bolt holes  628  may be provided in various embodiments. 
       FIG. 6  also shows the notched divider flange  426   b . The notched divider flange  426   b  includes a plurality of notches  626 . In the current embodiment, notched divider flange  426   b  includes four notches  626 , but in various embodiments any number of notches  626  may be provided. Notched divider flange  426   a  is similarly notched to notched divider flange  426   b  in the current embodiment. 
       FIG. 7  shows a cross-sectional view of the wheel hub  320  taken along line  7 - 7  in  FIG. 6 . Wheel hub  320  includes a plurality of cover bolt holes  722  for attachment of the cover  440  on a cover rim  724  of the wheel hub  320 . In the current embodiment, the wheel hub  320  includes twelve cover bolt holes  722  spaced evenly along the cover rim  724 , though any number of cover bolt holes  722  may be present in various embodiments.  FIG. 7  also shows an inner retaining shoulder  422 , similar to inner retaining shoulder  222 , formed in the inner end  428  of the wheel hub  320  and an outer retaining shoulder  424 , similar to outer retaining shoulder  224 , formed in an outer end  460  of the wheel hub  320 . The distance between the inner retaining shoulder  422  and the outer retaining shoulder  424  is a wheel hub clearance distance  700 .  FIG. 7  also shows that wheel hub  320  includes an inner channel  726  and an outer channel  728 . The inner channel  726  forms part of the sealed cavity  420 , though the inner channel  726  may not be included in the wheel hub  320  in various embodiments. The outer channel  728  may be a transition between the wheel flange  324  and the cover rim  724 , though the outer channel  728  may not be included in the wheel hub  320  in various embodiments. 
       FIG. 8  shows a front view of the spindle  330 . As shown in  FIG. 8 , the mounting flange  360  of the spindle  330  includes a plurality of bolt holes  834  for mounting of the seal  410  on the inner end  428 . The mounting flange  360  also includes a pair of dowel holes  832   a,b  for insertion of dowel pins to alight the seal  410  on the mounting flange  360 . The plurality of bolt holes  834  and the pair of dowel holes  832   a,b  are modifications added to the spindle  130  to create spindle  330 .  FIG. 8  also shows an outer end  432  of the spindle  330  includes a plurality of bolt holes  836  sized to accept the plurality of bolts  252  extending through the bearing retainer  250 .  FIG. 8  also shows a plurality of bolt holes  838  formed on the mounting flange  360  for mounting the brake assembly  150  on the spindle  330 . Any number of dowel holes  832 , bolt holes  834 , bolt holes  836 , or bolt holes  838  may be provided in various embodiments. 
       FIG. 9  shows a cross-sectional view of the spindle  330  taken along line  9 - 9  in  FIG. 8 . As shown in  FIG. 9 , the spindle  330  includes an inner cavity  934  extending from a mounting bore  932 , similar to mounting bore  132 , to an outer opening  936  defined in the outer end  432 . However, in various embodiments, the spindle  330  may not include an inner cavity  934 , and the disclosure of inner cavity  934  should not be considered limiting. In various embodiments, outer opening  936  may not be present, and outer end  432  may be closed. The spindle  330  also includes a plurality of bolt holes  938  spaced around a lower end of the mounting bore  932  for mounting the spindle  330  on the suspension cylinder  110 . The spindle  330  includes 25 bolt holes  938 , though any number of bolt holes  938  may be present in various embodiments. The plurality of bolt holes  838  are also show in  FIG. 9  in a bolt hole portion  962  of the mounting flange  360 . The distance between the outer end  432  of the spindle  330  and the bolt hole portion  962  of the mounting flange  360  is a first spindle clearance distance  900 . 
       FIG. 10  shows a detail cross-sectional view of the mounting flange  360  of the spindle  330 . As shown in  FIG. 10 , the mounting flange  360  includes a seal mounting surface  1062 . The plurality of bolt holes  834  and the pair of dowel holes  832   a,b  are defined in the seal mounting surface  1062 . The seal mounting surface  1062  is a modification in the spindle  330  over the spindle  130 , formed by a cutout  1064  in the mounting flange  260  to create mounting flange  360 . Cutout  1064  creates flat seal mounting surface  1062  to allow for easy mounting of the seal  410  on the spindle  330 . Cutout  1064  may be made by any process known in the art, including machining. However, in various embodiments, the cutout  1064  may not be included and the seal  410  may be mounted directly on unmodified spindle  130  or another modified spindle  330  not including the cutout  1064 .  FIG. 10  also shows a bearing spacer shoulder  1066  included in divider flange  360 . The bearing spacer shoulder  1066  abuts the bearing spacer  220 , providing a stop for the bearing spacer  220  in order for the bearing spacer  220  to hold the roller bearing  210   b  in place with the inner retaining shoulder  422 . The distance between the bearing spacer shoulder  1066  and the bolt hole portion  962  of the mounting flange  360  is a second spindle clearance distance  1000 . 
       FIG. 11  shows a front view of the cover  440 . As shown in  FIG. 11 , the cover  440  includes a plurality of bolt holes  1142  sized to accept the plurality of bolts  142  (show in  FIG. 1 ) to allow the cover  440  to be mounted on the wheel hub  320 . The cover  440  also includes a pair of bolt holes  1144   a,b  extending through the cover  440  and a pair of screw holes  1146   a,b . The cover  440  also includes a threaded check valve bore  1148  sized to accept the threaded check valve  540  (shown in  FIG. 5 ). The check valve bore  1148  is a modification of the cover  440  over the cover  140 . Any number of bolt holes  1142 , bolt holes  1144 , or screw holes  1146   a,b  may be present in various embodiments. 
       FIG. 12  shows a cross-sectional view of the cover  440  taken along line  12 - 12  in  FIG. 11 . As shown in  FIG. 12 , the cover  440  includes a cover mounting flange  1240 . The plurality of bolt holes  1142  extend through the cover mounting flange  1240 .  FIG. 12  also shows that the pair of screw holes  1146   a,b  do not extend completely through the cover  440 .  FIG. 12  also shows that the check valve bore  1148  is defined within a recess  1248  defined in an exterior of the cover  440 . 
       FIG. 13  shows a seal retainer  1300  of the seal  410 . As shown in  FIG. 13 , in the current embodiment, the seal retainer  1300  is ring-shaped and includes a plurality of bolt holes  1304 , a pair of dowel holes  1302   a,b , and a pair of threaded holes  1306   a,b . The dowel holes  1302   a,b  are sized to accept a pair of dowels and align the dowel holes  1302   a,b  with the dowel holes  622   a,b  of the wheel hub  320  or the dowel holes  832   a,b  of the spindle  330 , respectively, thereby aligning the seal retainer  1300  with the wheel hub  320  or the spindle  330 . The plurality of bolt holes  1304  are spaced to align with the plurality of bolt holes  624  of the wheel hub  320  or the plurality of bolt holes  834  of the spindle  330 , thereby permitting the seal retainer  1300  to be coupled with the wheel hub  320  or the spindle  330 . The dowel holes  1302   a,b  provide more precise alignment than the bolt holes  1304 , though the dowel holes  1302   a,b  may not be present in various embodiments, and the seal retainer  1300  may be attached to the wheel hub  320  or the spindle  330  by other methods in various embodiments, including welding, gluing, or being formed integrally with the wheel hub  320  or the spindle  330 . The threaded holes  1306   a,b  may function as jack screw holes and be used to separate the seal retainer  1300  from the wheel hub  320  or the spindle  330  by threading a pair of bolt through the threaded holes  1306   a,b  to push against the wheel hub  320  or the spindle  330 , though the threaded holes  1306   a,b  may not be present in various embodiments. Any number of bolts holes  1304 , dowel holes  1302 , and threaded holes  1306  may be present in various embodiments. 
       FIG. 14  shows a cross-sectional view of the seal retainer  1300  taken along line  14 - 14  in  FIG. 13 . As shown in  FIG. 14 , the seal retainer  1300  is L-shaped in the current embodiment, having a retaining lip  1400  extending from axially from a main body  1450  of the seal retainer  1300 . The retaining lip  1400  defines an O-ring sealing surface  1402  extending from a catch lip  1404  to an O-ring stop shoulder  1406 . The O-ring sealing surface  1402  thereby defines a taper  1408  sloping axially and radially inward towards the main body  1450 . The seal retainer  1300  also defines a mounting surface  1452  in the main body  1450  that may be placed in sealing engagement with the wheel hub  320  or the spindle  330 . The seal retainer  1300  also includes an O-ring channel  1460  defined in the mounting surface  1452  of the main body  1450 . 
       FIG. 15  shows a detail cross-sectional view of detail  15  in  FIG. 4 . As shown in  FIG. 15 , the seal  410  is mounted in the wheel assembly  300  between the wheel hub  320  and the spindle  330 . The seal  410  separates the brake assembly  150  from the roller bearings  210   a,b , forming the sealed cavity  420  between wheel hub  320  and spindle  330 . In the current embodiment, the seal  410  is a mechanical face seal, though other seals  410  separating the brake assembly  150  from the sealed cavity  420  may be present in various embodiments. 
     The seal  410  includes two seal retainers  1300   a,b . Seal retainer  1300   a  is mounted to the mounting flange  360  of the spindle  330  by a plurality of bolts  1504   a  and seal retainer  1300   b  is mounted to the inner end  428  of the wheel hub  320  by a plurality of bolts  1504   b . The seal  410  also includes a pair of seal rings  1510   a,b  and a pair of O-rings  1520   a,b . The seal rings  1510   a,b  are metallic in the current embodiment, being made of Duronit V cast iron, though other materials may be used in various embodiments. The O-rings  1520   a,b  are Hydrogenated Nitrile-Butadiene-Rubber (“HNBR”) in the current embodiment, though other materials may be used in various embodiments, such as Nitrile-Butadiene-Rubber (“NBR”), Silicone-Rubber (“VBR”), or Flourinated-Rubber (“FPM”). The seal retainer  1300   a  retains the seal ring  1510   a  and the O-ring  1520   a , and the seal retainer  1300   b  retains the seal ring  1510   b  and the O-ring  1520   b . Seal rings  1510   a,b  also contact each other. 
       FIG. 16  shows a detail cross-sectional view of detail  16  in  FIG. 15 . As shown in  FIG. 16 , the seal retainer  1300   a  is mounted to the mounting flange  360  of the spindle  330  by the plurality of bolts  1504   a  extending through a plurality of bolt holes  1304   a  of the seal retainer  1300   a  and through the plurality of bolt holes  834  of the mounting flange  360  when mounting surface  1452   a  of the seal retainer  1300   a  contacts the seal mounting surface  1062  of the mounting flange  360  and when the pair of dowel holes  1302   a,b  of the seal retainer  1300   a  align with the pair of dowel holes  832   a,b  of the mounting flange  360 , respectively. The pair of dowel holes  1302   a,b  of the seal retainer  1300   a  align with the pair of dowel holes  832   a,b  of the mounting flange  360  of the spindle  330  when dowel pins are inserted in the pair of dowel holes  832   a,b  of the mounting flange  360  and the seal retainer  1300   a  is thereafter placed against the mounting flange  360  so that the pair of dowel holes  1302   a,b  of the seal retainer  1300   a  accept the dowel pins. In various embodiments the dowel pins may be placed in the pair of dowel holes  1302   a,b  of the seal retainer  1300   a  first. 
     The seal retainer  1300   b  is mounted to the inner end  428  of the wheel hub  320  by the plurality of bolts  1504   b  extending through a plurality of bolt holes  1304   b  of the seal retainer  1300   b  and through the plurality of bolt holes  624  of the inner end  428  when mounting surface  1452   b  of the seal retainer  1300   b  contacts the inner end  428  of the wheel hub  320  and when the pair of dowel holes  1302   a,b  of the seal retainer  1300   b  align with the pair of dowel holes  622   a,b  of the inner end  428  of the wheel hub  320 , respectively. The pair of dowel holes  1302   a,b  of the seal retainer  1300   b  align with the pair of dowel holes  622   a,b  of the inner end  428  of the wheel hub  320  when dowel pins are inserted in the pair of dowel holes  622   a,b  of the inner end  428  of the wheel hub  320  and the seal retainer  1300   b  is thereafter placed against the inner end  428  so that the pair of dowel holes  1302   a,b  of the seal retainer  1300   b  accept the dowel pins. In various embodiments the dowel pins may be placed in the pair of dowel holes  1302   a,b  of the seal retainer  1300   b  first. 
       FIG. 16  also shows that, in the current embodiment, the seal  410  includes a pair of O-rings  1610   a,b  disposed within O-ring channels  1460   a,b  of the seal retainers  1300   a,b , respectively. O-ring  1610   a  thereby provides a fluid seal between the seal retainer  1300   a  and seal mounting surface  1062  of the mounting flange  360 , and O-ring  1610   b  thereby provides a fluid seal between the seal retainer  1300   b  and inner end  428  of the wheel hub  320 . 
       FIG. 16  also shows the interaction of the seal retainer  1300   a,b , the seal rings  1510   a,b , and the O-rings  1520   a,b . The seal rings  1510   a,b  are each L-shaped and include a face sealing surface  1616   a,b  and an O-ring sealing surface  1612   a,b , respectively. The face sealing surfaces  1616   a,b  face axially towards each other and contact each other. In the current embodiment, the face sealing surfaces  1616   a,b  are polished to allow the face sealing surfaces  1616   a,b  to slide easily against each other to allow rotation of the face sealing surfaces  1616   a,b , and thereby the wheel hub  320  and the spindle  330 , relative to each other while providing a fluid-tight seal between the seal rings  1510   a,b . The face sealing surfaces  1616   a,b  taper away from each other towards a radially inward portion of each seal ring  1510   a,b , forming a wedge-shaped gap  1618  facing into the sealing cavity  420  to allow for bearing oil to lubricate and cool the face sealing surfaces  1616   a,b  during rotation and for any potential wear of the face sealing surfaces  1616   a,b  to cause the face sealing surfaces  1616   a,b  to shift towards the gap  1618 . 
     The O-ring sealing surfaces  1612   a,b  each contact the O-rings  1520   a,b , respectively, which contact the O-ring sealing surfaces  1402   a,b , of the seal retainers  1300   a,b . The O-rings  1520   a,b  thereby seal the space between the seal retainers  1300   a,b  and the seal rings  1510   a,b , respectively. The O-rings  1520   a,b  have a diameter sized to bias the O-rings  1520   a,b  towards catch lips  1404   a,b  of the seal retainers  1300   a,b , respectively. However, when the seal rings  1510   a,b  contact each other along face sealing surface  1616   a,b , the O-ring sealing surfaces  1612   a,b  of the seal rings  1510   a,b  provide a wedging action, pushing the O-rings  1520   a,b  radially inward along the O-ring sealing surfaces  1402   a,b  of the seal retainers  1300   a,b , respectively. This wedging action strengthens the seal of the O-rings  1520   a,b  against the O-ring sealing surfaces  1402   a,b  of the seal retainers  1300   a,b  and against the O-ring sealing surfaces  1612   a,b  of the seal rings  1510   a,b , respectively. When the wheel hub  320  rotates, the seal retainer  1300   b  rotates with the wheel hub  320 , rotating the O-ring  1520   b  and thereby the seal ring  1510   b , and the seal  410  thereby seals the sealed cavity  420  while allowing the wheel hub  320  and the spindle  330  to rotate relative to each other. 
       FIG. 16  also shows the distance between the seal mounting surface  1062  and the inner end  428 , which is also the axial width  1600  of the seal  410 . The axial width  1600  may be measured to determine the size of the cutout  1064  to form mounting flange  360 . In the current embodiment, the cutout  1064  is sized to allow for the seal  410  to fit between the spindle  330  and the wheel hub  320  within a range of distances between the spindle  330  and the wheel hub  320  based on a tolerance of the seal  410 . Cutouts  1064 , all of the same size, may therefore be machined into multiple wheel assemblies  100  so long as the distance between the spindle  230  and the wheel hub  220  of each wheel assembly  100  is within the range of the tolerance of the seal  410 . 
     To modify the wheel assembly  100  to create wheel assembly  300 , the wheel hub  120  is removed from attachment to the spindle  130  by removing the cover  140 , the bearing retainer  250 , and roller bearing  210   a  and detaching brake assembly  150  from the spindle  130  and then from the wheel hub  120 . The size of the cutout  1064  necessary to create axial width  1600  between the inner end  428  of the spindle  330  and the seal mounting surface  1062  of the spindle  330  may be measured after removing the brake assembly  150  and before removing the wheel hub  120  from the spindle  130 . In embodiments where the size of the cutout  1064  is previously known or calculated to allow for the tolerance of the seal  410 , no measurement may be taken. 
     After removing the wheel hub  120 , inner end  228  of the wheel hub  120  may be modified with the plurality of bolt holes  624  and the pair of dowel holes  622   a,b  by drilling and/or tapping to create modified wheel hub  320 . The inner end  228  may also be machined to form a mounting surface in various embodiments, and a datum reference point such as the inner retaining shoulder  222  may be used to precisely machine the inner end  228  to the desired dimensions. The wheel hub clearance distance  700  may then be measured, as well as the first spindle clearance distance  900  and the second spindle clearance distance  1000 . The size of the cutout  1064  may thereafter be calculated, if not already known and if not measured after removal of the brake assembly  150 , using the first spindle clearance distance  900 , the second spindle clearance distance  1000 , the wheel hub clearance distance  700 , the axial width of the bearing spacer  220 , the axial width of both roller bearings  210   a,b , and any gap between the bearing retainer  250  and the outer end  432  of the spindle  330 . Any gap between the bearing retainer  250  and the outer end  432  of the spindle  330  may be shimmed in various embodiments. 
     The cutout  1064  is thereafter formed by machining or other known methods, creating seal mounting surface  1062 . The cutout  1064  may be formed relative to a datum reference point such as the bearing spacer shoulder  1066  to ensure that the cutout  1064  is precisely sized. The plurality of bolt holes  834  and the pair of dowel holes  832   a,b  are then added by drilling and/or tapping, creating modified spindle  330 . Prior to installing the seal retainers  1300   a,b  on the spindle  330  and the wheel hub  320 , respectively, the O-rings  1520   a,b  and the seal rings  1510   a,b  may be installed on each seal retainer  1300   a,b , respectively. The seal retainer  1300   a  may then be doweled and bolted to the seal mounting surface  1062  of the spindle  330  and the seal retainer  1300   b  may be doweled and bolted to the inner end  428  of the wheel hub  320 . The wheel hub  320  may thereafter be mounted on the spindle  330  with bearing spacer  220 , roller bearings  210   a,b , bearing retainer  250 , placing the face sealing surfaces  1616   a,b  in contact with each other, thereby forming seal  410 . 
     The cover  140  may be modified by drilling and taping check valve bore  1148 , creating cover  440 . The threaded check valve  540  may then be threaded into the check valve bore  1148 . The cover  440  may be mounted on the wheel hub  320 , thereby forming sealed cavity  420 . The sealed cavity  420  may thereafter be filled with bearing oil. In the current embodiment the sealed cavity  420  may be injected with between 13 and 15 gallons of bearing oil, though different amounts of bearing oil may be used in various embodiments. Bearing oil may be injected through one of the pair of bolt holes  1144   a,b  or any other holes through any of the cover  440 , the wheel hub  320 , the spindle  330 , the bearing retainer  250 , or any other opening that provides access to the interior of the sealed cavity  420 . Bearing oil may be injected in the lower of the bolt holes  1144   a,b  to prevent the oil level within the sealed cavity  420  from rising to or above the check valve bore  1148 , preventing oil from entering the check valve  540 . To drain bearing oil from the sealed cavity  420 , the wheel hub  320  may be rotated to place drainage port  520  at the lowest point of the sealed cavity  420  and the drainage port  520  may be unplugged, allowing the bearing oil to drain from the sealed cavity  420 . 
     One should note that conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular embodiments or that one or more particular embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. 
     It should be emphasized that the above-described embodiments are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Any process descriptions or blocks in flow diagrams should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included in which functions may not be included or executed at all, may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the present disclosure. Further, the scope of the present disclosure is intended to cover any and all combinations and sub-combinations of all elements, features, and aspects discussed above. All such modifications and variations are intended to be included herein within the scope of the present disclosure, and all possible claims to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure.