Abstract:
A tire inflation system having a spindle that has a spindle fastener hole and spindle passage through which a pressurized gas flows for inflating a tire. An adapter or a fastener tube may inhibit pressurized gas from flowing from the spindle passage into the spindle fastener hole.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. application Ser. No. 14/048,112, filed Oct. 8, 2013, the disclosure now U.S. Pat. No. 9,452,645, of which is hereby incorporated in its entirety by reference herein. 
    
    
     TECHNICAL FIELD 
     This patent application relates to a tire inflation system in which pressurized gas is routed through a spindle. 
     BACKGROUND 
     A tire inflation system is disclosed in U.S. Pat. No. 7,931,061. 
     SUMMARY 
     In at least one embodiment, a tire inflation system is provided. The tire inflation system may include a spindle, an adapter, a fitting, and a fastener. The spindle may rotatably support a wheel and may include a spindle passage and a spindle fastener hole. Pressurized gas may flow through the spindle passage. The spindle fastener hole may extend through the spindle and may intersect the spindle passage. The adapter may be disposed in the spindle passage. The adapter may include an adapter fastener hole and an adapter passage. The adapter fastener hole may be aligned with the spindle fastener hole. The adapter passage may receive the pressurized gas from the spindle passage. The adapter passage may not be fluidly connected to the adapter fastener hole. The fitting may be disposed proximate the adapter. The fitting may receive the pressurized gas from the adapter passage and may be fluidly connected to the tire. The fastener may extend through the spindle fastener hole and the adapter fastener hole. 
     In at least one embodiment, a tire inflation system is provided. The tire inflation system may include a spindle, a fitting, a fastener tube, and a fastener. The spindle may rotatably support a wheel and may include a spindle passage and a spindle fastener hole. The spindle passage may be disposed along an axis. Pressurized gas for inflating a tire may flow through the spindle passage. The spindle fastener hole may extend through the spindle and may intersect the spindle passage. The fitting may be disposed in the spindle passage. The fitting may receive pressurized gas from the spindle passage and may be fluidly connected to the tire. The fastener tube may extend through the spindle fastener hole. The fastener tube may inhibit pressurized gas from flowing from the spindle passage into the spindle fastener hole. The fastener may extend through the fastener tube to inhibit movement of the spindle nut that is disposed on the spindle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a section view of an exemplary wheel end assembly and a tire inflation system. 
         FIG. 2  is a fitting that may be provided with a wheel end assembly. 
         FIG. 3  is a top section view of a portion of the wheel end assembly with the adapter of  FIG. 2 . 
         FIG. 4  is a perspective view of a first embodiment of an adapter that may be provided with the tire inflation system. 
         FIG. 5  is a top section view of a portion of the wheel end assembly with the adapter of  FIG. 4 . 
         FIG. 6  is a perspective view of a second embodiment of an adapter that may be provided with the tire inflation system. 
         FIG. 7  is a top section view of a portion of the wheel end assembly with the adapter of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
     Referring to  FIG. 1 , a portion of an exemplary axle assembly  10  is shown. The axle assembly  10  may be provided with a motor vehicle like a truck, bus, farm equipment, military transport or weaponry vehicle, or cargo loading equipment for land, air, or marine vessels, or a trailer that may be provided with a motor vehicle. 
     The axle assembly  10  may be configured as a non-drive axle in one or more embodiments. As such, the axle assembly  10  may not receive torque from a power source, such as an internal combustion engine or electric motor, that may be used to propel the vehicle. The axle assembly  10  may or may not be steerable. In a non-drive axle configuration, the axle assembly  10  may include an axle housing  20 , a spindle  22 , and a wheel end assembly  24 . 
     The axle housing  20  may receive or support various components of the axle assembly  10 . In addition, the axle housing  20  may facilitate mounting of the axle assembly  10  to the vehicle. 
     The spindle  22  may be provided with or may be fixedly positioned with respect to the axle assembly  10 . In a steerable configuration, the spindle  22  may be provided with or may be fixedly positioned with respect to a steering knuckle rather than the axle housing  20 . The spindle  22  may generally extend along but may not rotate about an axis  26 . In at least one embodiment, the spindle  22  may include a first spindle end surface  30 , a second spindle end surface  32 , an internal surface  34 , an external surface  36 , a spindle passage  38 , and a spindle fastener hole  40 . 
     The first spindle end surface  30  may be disposed proximate or may engage the axle housing  20 . Alternatively, the first spindle end surface  30  may be omitted in a configuration in which the spindle  22  is integrally formed with the axle housing  20  or is not provided as a separate component. The second spindle end surface  32  may be disposed opposite the first spindle end surface  30 . 
     The internal surface  34  may extend between the first spindle end surface  30  and the second spindle end surface  32  and may at least partially define the spindle passage  38 . Pressurized gas for inflating a tire may flow through the spindle passage  38 . For example, the spindle passage  38  may define a conduit that receives pressurized gas or the spindle passage  38  may receive a conduit, such as a hose, tubing or the like that may receive pressurized gas and that may extend at least partially through the spindle passage  38 . 
     The external surface  36  may be disposed opposite the internal surface  34 . The external surface  36  of the spindle  22  may support one or more wheel bearings that may rotatably support the wheel end assembly  24  as will be discussed in more detail below. 
     The spindle fastener hole  40  may be configured to receive a fastener  42 , such as a cotter pin, that may help secure or inhibit movement of a spindle nut  44  that may be disposed on the spindle  22 . The spindle nut  44  may help inhibit axial movement of the wheel end assembly  24 . The spindle fastener hole  40  may extend along a spindle fastener hole axis  46 . The spindle fastener hole axis  46  may intersect and may be disposed substantially perpendicular to the axis  26  in one or more embodiments. The spindle fastener hole  40  may intersect the spindle passage  38  and may extend completely through the spindle  22  such that the spindle passage  38  may separate or bisect the spindle fastener hole  40 . 
     The wheel end assembly  24  may be rotatably disposed on the spindle  22 . The wheel end assembly  24  may include a hub  50 , a hub cap  52 , wheel end seal assembly  54 , a brake subsystem  56 , a wheel  58 , and a tire  60 . 
     The hub  50  may be rotatably disposed on the spindle  22  and may be configured to rotate about the axis  26 . For instance, one or more wheel bearings may be mounted on spindle  22  and may rotatably support the hub  50 . In  FIG. 1 , a first wheel bearing  70  and a second wheel bearing  72  are provided in a cavity  74  that is located between the spindle  22  and the hub  50 . The first wheel bearing  70  may be disposed inboard or further from the second spindle end surface  32  than the second wheel bearing  72 . 
     The hub cap  52  may be coupled to the hub  50  with one or more fasteners  76 . As such, the hub cap  52  may rotate with the hub  50 . 
     The wheel end seal assembly  54  may be disposed between the spindle  22  and the hub  50 . The wheel end seal assembly  54  may inhibit contaminants from entering the cavity  74  and may help retain lubricant in the cavity  74 . In at least one embodiment, the wheel end seal assembly  54  may be fixedly disposed with respect to the hub  50  and may rotate about the axis  26  and with respect to the spindle  22 . 
     The brake subsystem  56  may be adapted to slow or inhibit rotation of at least one associated wheel  58 . For example, the brake subsystem  56  may be configured as a friction brake, such as a drum brake or a disc brake. In  FIG. 1 , a portion of the brake subsystem  56  is shown with a drum brake configuration. In a drum brake configuration, a brake drum  80  may be fixedly disposed on the hub  50  with one or more fasteners  82 , such as wheel lug studs. The brake drum  80  may extend continuously around brake shoe assemblies (not shown) that may be configured to engage the brake drum  80  to slow rotation of an associated wheel  58 . 
     The wheel  58  may be fixedly disposed on the hub  50 . For example, the wheel  58  may be mounted on the hub  50  via the fasteners  82 . More specifically, the wheel  58  may have a wheel mounting flange  84  that may have a set of holes that may each receive a fastener  82 . A lug nut  86  may be threaded onto each fastener to secure the wheel  58  to the fasteners  82  and the hub  50 . The lug nut  86  may engage or may be disposed proximate an outboard side  88  of the wheel mounting flange  84  that may face away from the brake drum  80  or toward the hub cap  52 . The wheel  58  may be configured to support the tire  60 . The tire  60  may be a pneumatic tire that may be inflated with a pressurized gas or pressurized gas mixture. 
     A tire inflation system  90  may be associated with the wheel end assembly  24 . The tire inflation system  90  may be disposed on the vehicle and may be configured to provide a pressurized gas or pressurized gas mixture to one or more tires  60 . For clarity, the term “pressurized gas” may refer to either a pressurized gas or a pressurized gas mixture. The tire inflation system  90  may include a control system that may monitor and control the inflation of one or more tires  60 , a pressurized gas source  92 , and a gas supply subsystem  94 . 
     The pressurized gas source  92  may be configured to supply or store a volume of a pressurized gas or pressurized gas mixture, like air or nitrogen. For example, the pressurized gas source  92  may be a tank and/or a pump like a compressor. The pressurized gas source  92  may be disposed on the vehicle and may provide a pressurized gas or pressurized gas mixture at a pressure that is greater than or equal to a desired inflation pressure of a tire  60 . As such, the pressurized gas source  92  may inflate a tire or maintain a desired tire pressure. 
     The gas supply subsystem  94  may fluidly connect the pressurized gas source  92  to the tire  60 . The gas supply subsystem  94  may include one or more conduits, such as a hose, tubing, pipe, or combinations thereof. In  FIG. 1 , a first conduit  100 , a connection conduit  102 , and a second conduit  104  are shown. The first conduit  100  may receive pressurized gas from the pressurized gas source  92  and may fluidly connect the pressurized gas source  92  to the spindle passage  38 . The connection conduit  102  may receive pressurized gas from the spindle passage  38  and may supply pressurized gas to the second conduit  104 . For example, the connection conduit  102  may extend through a hole in the hub cap  52  and may be connected to the second conduit  104  with a fitting  106 . The second conduit  104  may receive pressurized gas from the connection conduit  102  and may supply pressurized gas to the tire  60 . The routing of the conduits between the pressurized gas source  92  and a tire  60  that is shown in  FIG. 1  is exemplary and is not meant to be limiting as other conduit routing paths may be provided. In addition, one or more valves may be associated with or provided with a conduit to enable or disable the flow of the pressurized gas from the pressurized gas source  92  to one or more tires  60 . The flow of pressurized gas is represented by the arrows located near the conduits in  FIG. 1 . 
     Referring to  FIGS. 3, 5, and 7 , exemplary interfaces between the wheel end assembly  24  and the gas supply subsystem  94  are shown. In each configuration, pressurized gas may be routed through the spindle passage  38  to the connection conduit  102 . In addition, the fastener  42  is omitted from  FIGS. 3, 5, and 7  for clarity. 
     Referring to  FIGS. 2 and 3 , a first example of an interface is shown. In this embodiment, a fitting  110  and a fastener tube  112  are employed. 
     The fitting  110  may receive pressurized gas from the spindle passage  38  and may help fluidly connect the pressurized gas source  92  to the tire  60 . The fitting  110  may have a first fitting end surface  120 , a second fitting end surface  122 , a fitting hole  124 , a first outer fitting surface  126 , a second outer fitting surface  128 , and a fitting step surface  130 . 
     The first fitting end surface  120  may be disposed at an end of the fitting  110 . The first fitting end surface  120  may be disposed opposite the second fitting end surface  122  and may be received in the spindle passage  38  as is best shown in  FIG. 3 . In addition, the first fitting end surface  120  may be spaced apart from the fastener tube  112 . 
     The fitting hole  124  may extend from the first fitting end surface  120  to the second fitting end surface  122 . The fitting hole  124  may receive the connection conduit  102 . In addition, the fitting hole  124  may receive pressurized gas from the spindle passage  38  and may route pressurized gas to the connection conduit  102 . A seal may be disposed in the fitting hole  124  between the connection conduit  102  and the fitting  110  to help inhibit leakage of pressurized gas between the fitting  110  and the connection conduit  102 . 
     The first outer fitting surface  126  may extend from the first fitting end surface  120  toward the second fitting end surface  122 . The first outer fitting surface  126  may at least partially define an outside circumference of the fitting  110 . In addition, the first outer fitting surface  126  may be disposed in the spindle passage  38  and may engage the spindle  22  to help inhibit leakage of pressurized gas between the fitting  110  and the spindle  22 . 
     The second outer fitting surface  128  may extend from the second fitting end surface  122  toward the first fitting end surface  120  and the fitting step surface  130 . The second outer fitting surface  128  may at least partially define an outside circumference of the fitting  110  and may have a larger diameter than the first outer fitting surface  126 . 
     The fitting step surface  130  may extend from the first outer fitting surface  126  to the second outer fitting surface  128 . In at least one embodiment, the fitting step surface  130  may engage the second spindle end surface  32  to help position and inhibit axial movement of the fitting  110  with respect to the spindle  22 . 
     Referring to  FIG. 3 , the fastener tube  112  may receive the fastener  42  (which is not shown in  FIG. 3  for clarity) and may extend through the spindle fastener hole  40  to inhibit or prevent pressurized gas from exiting the spindle  22  via the spindle fastener hole  40 . The fastener tube  112  may have a tubular configuration and may have a fastener tube hole  134  through which the fastener  42  may extend. The fastener tube  112  may extend along an axis, such as the spindle fastener hole axis  46  and may be disposed substantially perpendicular to the axis  26 . The fastener tube  112  may be spaced apart from the fitting  110  and may be smaller than the spindle passage  38 . As such, pressurized gas may flow around the fastener tube  112  to reach the fitting  110 . The fastener tube  112  may be secured to the spindle  22  in any suitable manner, such as with an interference fit and/or one or more seals that may inhibit leakage of pressurized gas between the spindle  22  and the fastener tube  112 . 
     Referring to  FIGS. 4 and 5 , a second example of an interface is shown. In this embodiment, the fitting  110  and an adapter  140  are employed. The adapter  140  is best shown in  FIG. 4 . 
     The adapter  140  may receive pressurized gas from the spindle passage  38  and may route the pressurized gas to the fitting  110 . The adapter  140  may have a first end surface  150 , a second end surface  152 , a first outer surface  154 , a second outer surface  156 , an outer step surface  158 , an internal surface  160 , a first inner surface  162 , a second inner surface  164 , an inner step surface  166 , an adapter fastener hole  168 , and at least one adapter passage  170 . 
     The first end surface  150  may be disposed at an end of the adapter  140 . The first end surface  150  may be received in the spindle passage  38  as is best shown in  FIG. 5 . In addition, the first end surface  150  may be spaced apart from the spindle  22 . 
     The second end surface  152  may be disposed opposite the first end surface  150 . The second end surface may be disposed proximate or may engage a surface of the fitting  110 , such as the fitting step surface  130  to help inhibit leakage of pressurized gas between the fitting  110  and the adapter  140 . 
     The first outer surface  154  may extend from the first end surface  150  toward the second end surface  152 . The first outer surface  154  may at least partially define an outside circumference of the adapter  140 . In addition, the first outer surface  154  may be disposed in the spindle passage  38  and may engage the spindle  22  to inhibit or prevent leakage of pressurized gas between the spindle  22  and the adapter  140 . 
     The second outer surface  156  may extend from the second end surface  152  toward the first end surface  150  and the outer step surface  158 . The second outer surface  156  may at least partially define an outside circumference of the adapter  140  and may have a larger diameter than the first outer surface  154 . 
     The outer step surface  158  may extend from the first outer surface  154  to the second outer surface  156 . In at least one embodiment, the outer step surface  158  may engage the second spindle end surface  32  to help position and inhibit axial movement of the adapter  140  with respect to the spindle  22  and/or to inhibit leakage of pressurized gas between the spindle  22  and the adapter  140 . 
     The internal surface  160  may be disposed between and may be spaced apart from the first end surface  150  and the second end surface  152 . In at least one embodiment, the internal surface  160  may be axially positioned between first end surface  150  and the outer step surface  158 . The internal surface  160  may be spaced apart from the fitting  110  and the connection conduit  102  such that a chamber  180  is provided between the fitting  110  and adapter  140  that may fluidly connect the adapter passage  170  to the fitting hole  124  and/or connection conduit  102 . 
     The first inner surface  162  may extend from the second end surface  152  toward the internal surface  160 . The first inner surface  162  may at least partially define an inside circumference of the adapter  140 . In addition, the first inner surface  162  may receive and may engage the fitting  110  to inhibit leakage of pressurized gas between the fitting  110  and the adapter  140 . 
     The second inner surface  164  may extend from the internal surface  160  toward the second end surface  152  and may partially define the chamber  180 . The second inner surface  164  may at least partially define an inside circumference of the adapter  140  and may have a smaller diameter than the first inner surface  162 . 
     The inner step surface  166  may extend from the first inner surface  162  to the second inner surface  164 . In at least one embodiment, the inner step surface  166  may engage a surface of the fitting  110 , such as the first fitting end surface  120  to help position and inhibit axial movement of the fitting  110  with respect to the adapter  140  and/or to inhibit leakage of pressurized gas between the fitting  110  and the adapter  140 . 
     The adapter fastener hole  168  may receive the fastener  42  (which is not shown in  FIG. 5  for clarity). The adapter fastener hole  168  may extend through the adapter  140  such that the adapter fastener hole  168  may have two openings in the first outer surface  154 . The adapter fastener hole  168  may be located between the first end surface  150  and the internal surface  160  and may be spaced apart from the adapter passage  170  to inhibit or prevent pressurized gas from exiting the adapter  140  via the adapter fastener hole  168 . As such, the adapter passage  170  may not be fluidly connected to the adapter fastener hole  168 . The adapter fastener hole  168  may extend along an axis, such as the spindle fastener hole axis  46  and may be disposed substantially perpendicular to the axis  26 . 
     At least one adapter passage  170  may be provided with the adapter  140 . In the embodiment shown in  FIGS. 4 and 5 , two adapter passages  170  are shown. The adapter passages  170  may be spaced apart from each other and may be disposed on opposite sides of the axis  26  and the adapter fastener hole  168 . In addition, the adapter passages  170  may extend substantially parallel to each other in one or more embodiments. Each adapter passage  170  may extend from the first end surface  150  to the internal surface  160  and/or the inner step surface  166 . In addition, each adapter passage  170  may be disposed between and may be spaced apart from the first outer surface  154  and the adapter fastener hole  168  to help inhibit leakage of pressurized gas from the adapter  140 . The adapter passage  170  may receive pressurized gas from the spindle passage  38  and may route pressurized gas to the chamber  180  and the connection conduit  102 . 
     Referring to  FIGS. 6 and 7 , a third example of an interface is shown. In this embodiment, the fitting  110  and an adapter  140 ′ are employed. 
     The adapter  140 ′ may have a similar configuration as the adapter  140  shown in  FIG. 4 , but may have an adapter passage  170 ′ with a different configuration and may include at least one flat  190 ′. 
     In the embodiment shown in  FIGS. 6 and 7 , two flats  190 ′ are provided. The flats  190 ′ may be spaced apart from each other and may be disposed on opposite sides of the axis  26  and the adapter fastener hole  168 . In addition, the flats  190 ′ may extend substantially parallel to each other in one or more embodiments. Each flat  190 ′ may extend from the first end surface  150  to a flat step surface  192 ′. The flat step surface  192 ′ may be disposed between the first end surface  150  and the outer step surface  158  and may extend from the flat  190 ′ to the first outer surface  154 . The flat step surface  192 ′ may extend substantially perpendicular to the axis  26  in one or more embodiments. 
     At least one adapter passage  170 ′ may be provided with the adapter  140 ′. In the embodiment shown in  FIG. 6 , two adapter passages  170 ′ are shown. The adapter passages  170 ′ may be spaced apart from each other and may be disposed on opposite sides of the axis  26 . In addition, the adapter passages  170 ′ may be coaxially disposed in one or more embodiments. Each adapter passage  170 ′ may extend from a flat  190 ′ to the chamber  180 . For instance, the adapter passage  170 ′ may extend from a flat  190 ′ to the internal surface  160  and/or the second inner surface  164 . In addition, each adapter passage  170 ′ may be disposed between a corresponding flat  190 ′ and the adapter fastener hole  168  such that the adapter passage  170 ′ is spaced apart from the adapter fastener hole  168  to inhibit leakage of pressurized gas from the adapter  140 ′ through the adapter fastener hole  168 . As such, the adapter passage  170 ′ may not be fluidly connected to the adapter fastener hole  168 . In addition, the adapter passage  170 ′ may be completely disposed between the adapter fastener hole  168  and the fitting  110 . Pressurized gas in the spindle passage  38  may flow between the spindle  22  and the flat  190 ′ and to the adapter passage  170 ′, which may route the pressurized gas to the chamber  180  and the connection conduit  102 . 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.