Rotary wheel-end assembly for tire inflation system

A rotary wheel-end assembly (90) is provided that includes a disc-like member (26) that when secured to a vehicular wheel hub (16) is operative to rotate relative a stationary axle spindle as well as provide a first chamber (28) about the end of axle (2). Assembly (90) has a passageway (36) therethrough for conveying pressurized air to the tire from axle (2) and includes a cover (42) secured in spaced-apart relationship to a side of member (26) facing away from axle (2) to provide a second chamber (46). Chambers (28) and (46) are adapted to hold a lubricant for lubricating frictional interaction between rotary assembly (90) and stationary axle (2) as well as wheel bearings (12) and at least one opening (40) is provided through member (26) for providing fluid communication between chambers (28) and (46) in addition to the preferable inclusion of at least one resilient closable member (48) through cover (42) for conveying lubricant into chamber (46).

This invention relates generally to an assembly for use with central tire 
inflation systems CTIS, also known as onboard inflation systems and tire 
traction systems, and more particularly to a rotary assembly adapted for 
mounting to a rotary wheel hub of a stationary (non-driven) axle and 
operable to transfer fluid, such as air, between the tire and the axle 
whilst providing a liquid lubricant, such as a suitable oil, to lessen 
rotational friction between the rotary assembly and the stationary 
(non-rotating) axle. 
BACKGROUND OF THE INVENTION 
In (CTIS) systems, the inflation pressure of one or more vehicle tires is 
characteristically controlled from a remote location (usually the vehicle 
cab) using an onboard source of pressurized fluid which is commonly 
compressed air from the vehicle air brake compressor and/or a compressed 
air reservoir. 
In order to transfer the air between the axle and the tire, a variety of 
wheel-end valve assemblies have been developed such as disclosed in U.S. 
Pat. Nos.: 2,634,781; 2,989,999; 3,276,502; 4,434,833; 4,437,504; 
4,640,331; 4,678,017; and 4,724,879, the disclosures of which are 
incorporated herein by reference. 
Such prior art assemblies, although purportedly effective in transferring 
fluid (air) between an axle and a tire, are characteristically expensive 
and complex in design and have not heretofor addressed the problem of 
providing a rotary assembly for transferring air conveyed through a 
stationary axle to a rotary tire that is inexpensive and simple in design 
and that is adapted to provide a liquid lubricant, such as oil, for 
lessening friction between the rotary assembly and stationary axle. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to provide a rotary 
wheel-end assembly for transferring a fluid, such as air, between a rotary 
tire and a non-driven (non-rotating) axle. 
It is another object of this invention to provide a rotary wheel-end 
assembly for transferring a fluid, such as air, between a stationary 
vehicular axle and a rotary tire that is inexpensive and relatively simple 
in design. 
It is still another object of this invention to provide a rotary wheel-end 
assembly for transferring a fluid, such as air, between a non-rotating 
axle and a rotary tire that is operative to provide a liquid lubricant for 
lessening friction between the assembly and the axle.

DESCRIPTION OF SOME PREFERRED EMBODIMENTS 
Rotary assembly 80 of FIG. 1 is secured by means such as bolts 24 to an 
annular surface 22 of an axle hub 16 facing theretowards. Hub 16 is 
rotatably mounted by means of suitable bearings 12 (only one shown) on a 
not-rotating axle spindle 2. Axle 2 has external threads 8 at its end that 
are threadingly engaged by a nut 10 that, upon rotational advancement 
along threads 8, presses against washer 14 to hold bearing 12 in place and 
enable hub 16 to rotate about axle 2. Axle 2 commonly includes a 
transverse opening 18 through threads 8 for receiving a cotter pin or the 
like to hold nut 19 in place. Although not shown, a tire rim and tire are 
secured to hub 16 and rotate in unison therewith about axle 2. 
Axle 2 is a non-driven (non-rotating) axle of a vehicle having a central 
tire inflation system (CTIS) that includes a source of pressurized fluid 
(commonly air) as previously described. Axle 2 has a channel 4 
therethrough communicating with an open-ended bore 6 at the end thereof 
facing towards assembly 80 for conveying the fluid therethrough from the 
pressurization source as shown by the arrow. Since axle 2 is non-rotating, 
it is not an absolute requirement that axle 2 have a channel 4 
therethrough since the fluid could be conveyed to bore 6 by means of an 
exterior conduit that is in fluid communication with bore 6. 
Assembly 80 includes a disc-like member 26 defining a first chamber 28 
between hub 16 and a surface of member 26 facing theretowards within 
annular surface 22 when assembly 80 is secured to annular surface 22. 
Assembly 80 includes a projection 30 having a substantially cylindrical 
portion thereof extending into bore 6 therefrom. Projection 30 is adapted 
to enable assembly 80 to rotate relative bore 6 and axle 2. 
The radially outer surface of projection 30 within the radially inner 
surface of the axle bore 6 is provided with means for sealing against 
fluid leakage between whilst enabling assembly 80 to rotate relative bore 
6 and axle 2. 
Preferably the sealing means is provided by at least one resilient member 
such as a resilient "0" ring 34 disposed in an annular groove (not 
referenced) in the outer surface of projection 30. 
Bore 6 preferably includes a tubular liner or sleeve 20 as a wear surface 
therewithin for member(s) 34 to bear against and to prevent any damage 
that might arise due to the entrance of opening 18 into bore 6. Sleeve 20 
also provides a means to seal transverse opening 18, previously described, 
from bore 6. 
Assembly 80 includes a passageway 36 extending through projection 30 and 
disc-like member 26 to an outlet port 38 that is adapted by means of 
suitable threads or the like to enable a connection (not shown) to be made 
thereto for conveying the inflation fluid (air) to the tire. 
Disc-like member 26 of assembly 80 includes at least one opening 40 
therethrough that for assembly 80 is closable by means of a threaded bolt 
25 or other means that will ensure that opening 40 remains closed while 
hub 16 and assembly 80 is rotating about axle 2. 
Opening 40 is adapted to enable a lubricant, such as a suitable lubricating 
oil, to be conveyed therethrough into chamber 28, (which is adapted to 
hold the lubricant) for lubricating bearing 12 and members 34 and 
projection 30. 
Assembly 80 is thus operable to be mounted upon an annular surface 22 of 
hub 16 concentrically surrounding the end of axle 2 and facing 
theretowards. Assembly 80 is operable to rotate relative stationary axle 2 
and to convey and transmit pressurized fluid such as air between axle 2 
and the tire as well as include means such as chamber 28 for holding 
lubricant for lubricating projection 30 to lessen rotational friction 
between rotary assembly 80 and stationary axle 2. 
Rotary assembly 90 of FIG. 2 is substantially the same as previously 
described assembly 80 excepting that it includes a cover member or plate 
42 secured in spaced-apart relationship to a side of disc-like member 26 
facing away from hub 16 defining a second chamber 46 therebetween. 
Cover member 42 is preferably secured to member 26 by means of spacing ring 
43 and bolts 24 used to secure assembly 90 to surface 22. 
Second chamber 46, like first chamber 28, is adapted to hold liquid 
lubricant. At least one opening 40 extends through disc-like member 26 to 
enable the lubricant to flow into chamber 28 from chamber 46. Means for 
preventing lubricant from leaking between cover member 42 and disc-like 
member 26 from chamber 43, from chamber 46 is preferably provided by a 
resilient member such as "0" ring 44 that is held in a compressed 
condition between a surface of disc-like member 26, spacing ring 43 and 
and cover member 42 secured thereto. 
Cover member 42 includes at least one closable opening 41 therethrough 
adapted to enable lubricant to be conveyed into chamber 46 without having 
to release cover member or plate 42 from member 26. Preferably the 
closable opening is provided by a closure member 48 secured thereacross 
that has a resiliently closable aperture 50. Closure member 48 can be 
removed to enable the lubricant to be conveyed into chamber 46 and 
replaced to contain the lubricant within chamber 46 and is additionally 
operable to act as a vent thru aperture 50 to vent any excessive pressure 
that may arise within chamber 46. 
Cover member or plate 42 is preferably made from a suitable transparent 
material so as to enable determination of the amount of lubricant in 
chamber 46 without having to remove cover member 42 from disc-like member 
26. 
Assembly 100 of FIG. 3 is substantially the same as previously described 
assembly 90 excepting that projection 30 (although extending from 
disc-like member 26 into bore 6) is not integral therewith. 
Projection 30 of assembly 100 is preferably press-fit into and extends for 
a prescribed distance from bore 6 and may include rotary spacer or seals 
47 thereabout in addition to a spacer 49 at an end thereof facing towards 
disc-like member 26 operable to maintain a cavity 51 thereabout enabling 
disc-like member 26 to rotate relative to projection 30 (which is 
stationary relative bore 6) whilst enabling the fluid to be transmitted 
across cavity 51 through passageway 36. 
The assembly of the invention provides a means for transferring fluid 
between a rotary tire and a stationary axle of a vehicle having a central 
tire inflation system while providing lubricant for lessening rotary 
friction between the assembly axle and wheel bearing element. 
The assembly of the invention may be made from any material predetermined 
suitable such as steel or an aluminum alloy and preferably includes a 
transparent cover member for determining the amount of lubricant being 
held within the assembly. 
Although some preferred embodiments of the present invention have been 
described with a certain degree of particularity, it is understood that 
various modifications may be resorted to without departing from the spirit 
of the invention as hereinafter claimed.