WO2015097697A1

WO2015097697A1 - Ctis assembly and method

Info

Publication number: WO2015097697A1
Application number: PCT/IL2014/051118
Authority: WO
Inventors: Ami KAMIL; Izik MINI
Original assignee: Rego Vehicles Ltd.
Priority date: 2013-12-24
Filing date: 2014-12-22
Publication date: 2015-07-02

Abstract

A vehicle drive axle tire inflation device for providing fluid communication between a vehicle fluid pressure source and the tire of a vehicle wheel. The device includes a wheel hub which has a hub splined member, and a drive shaft which has a mating drive splined member configured to mesh with the hub splined member and drive the wheel hub. One of the hub splined member and drive splined member includes a splined shaft and the other includes a mating splined coupling collar. The splined coupling collar includes at least one opening bored through its side wall. The device further includes a static sealed housing disposed about the coupling collar, by means of a rotary joint, forming a sealed chamber about the coupling collar. The sealed chamber is coupled to and in fluid communication with the at least one opening of the coupling collar and with the fluid pressure source. The device further includes at least one conduit defined by a gap at an interface between the coupling collar and the splined shaft, running there along in between and being in fluid communication with the opening and with the tire of the wheel, and is configured to communicate a fluid between the sealed chamber and the tire.

Description

CTIS ASSEMBLY AND METHOD

FIELD OF THE DISCLOSED TECHNIQUE

The disclosed technique generally relates to vehicles on wheels with pneumatic tires, and more particularly, to onboard tire inflation systems that continuously maintain the inflation pressure of the tires on moving vehicles.

BACKGROUND OF THE DISCLOSED TECHNIQUE

Automatic central tire inflation systems for vehicle tires are well known, often under the terminology of Central Tire Inflation Systems (CTIS). There exists a problem in CTIS whenever air pressure is to be supplied to the tires, particularly when the wheel is driven by a rotating shaft, of fluid communication between the static air supply source and the rotating wheel. Prior art designs have provided various solutions to this challenge.

US Patent No. 8,327,895 to Stech, entitled "Drive axle seal body and tire inflation system" discloses a sealing body disposed about a rotating drive axle and forming an air chamber thereabout. The drive axle is provided with an air conduit extending therein and communicating air from the air chamber to the center of the drive axle and for delivery to tires via the wheel at the center of the axle flange. The sealing body includes an air conduit in communication with the air chamber, and is configured to secure to remain stationary about the drive axle axially rotating therein. The sealing body is typically disposed between the drive axle splines and the wheel and forms an air seal thereabout. The sealing body may include a plurality of parts when the splines have a greater diameter than the remainder of the drive axle, but may also include a unitary body configured to be axially disposed over the splines when the splines have a diameter consistent with the drive axle.

US Patent No. 7,418,989 to Ingram, entitled "Rotary union assembly for use in air pressure inflation systems for tractor trailer tires" suggests a tire inflation system having a hub cap secured to the wheel, which is attached to an axle of a vehicle. The axle provides a source of pressurized air, and a rotary union assembly attachable to the exterior of the hub cap includes a rotating portion and a non-rotating portion. The rotating portion rotates with said hub cap, while the non-rotating portion includes at least a stationary shaft in fluid communication with a source of pressurized air. The shaft defines an air passage there through for conducting pressurized air from the source of pressurized air to the tire which is mounted to the wheel of the vehicle. US Patent No. 6,425,427 to Stech, entitled "On-axle tire inflation system" teaches a vehicle air supply system providing pressurized air from an axle of a vehicle to rotating tires to maintain a desired pneumatic pressure. The air supply system is adapted to be sealingly disposed within the hollow axle of the vehicle, having a rotary union disposed therein. An axle plug assembly is seated within the hollow axle, and has resilient members expanded there within to provide an air tight seal. A graphite seal is provided to minimize the friction between a rotating shaft coupled to an oil cap, and the stationary axle plug assembly.

US Patent No. 5,377,736 to Stech, entitled "Driven axle vehicle inflation system" discloses an air inflation system for tires on a vehicle having at least one driven axle in which the axle includes a longitudinal extending air passageway connected to each tire at the end of the axle and a rotatable air coupling connected between an air line and the air passageway. The coupling includes a stationary tubular sleeve surrounding the axle and first and second seals, respectively, at opposite ends of the sleeve in which the seals rotate with the axle and engage the axle. The seals are biased into engagement with the sleeve.

Further prior art designs are reviewed in US patent no. 6,145,558 to Schmitz. SUMMARY OF THE DISCLOSED TECHNIQUE

In accordance with one aspect of the disclosed technique, there is thus provided a vehicle drive axle tire inflation device for providing fluid communication between a vehicle fluid pressure source and the tire of a vehicle wheel. The device includes a wheel hub which has a hub splined member, and a drive shaft which has a mating drive splined member configured to mesh with the hub splined member and drive the wheel hub. One of the hub splined member and drive splined member includes a splined shaft and the other includes a mating splined coupling collar. The splined coupling collar includes at least one opening bored through its side wall. The device further includes a static sealed housing disposed about the coupling collar, by means of a rotary joint, forming a sealed chamber about the coupling collar. The sealed chamber is coupled to and in fluid communication with the at least one opening of the coupling collar and with the fluid pressure source. The device further includes at least one conduit defined by a gap at an interface between the coupling collar and the splined shaft, running there along in between and being in fluid communication with the opening and with the tire of the wheel, and is configured to communicate a fluid between the sealed chamber and the tire. Optionally, the splined shaft may include a shaft flange disposed at the point of engagement with the distal-end of the coupling collar; and the device may further include a seal interposed between the distal end of the coupling collar and the shaft flange.

The drive splined member may include a spindle which is coupled to a CV joint of a drive axle, or an outer stub of a CV Joint of a drive axle.

The rotary joint may include side bearings and annular seals, wherein the bearings and seals are attached to and surround the coupling collar.

Further optionally, the splined shaft may include a shaft flange disposed at the point of engagement with a distal-end of the coupling collar, wherein the coupling collar includes a collar flange having a diameter greater than that of the coupling collar, the collar flange being disposed about the collar at a distance from the distal-end of the coupling collar such that the static sealed housing is positioned about the coupling collar between the shaft flange and the collar flange; and wherein the rotary joint includes side bearings and annular seals attached to, surrounding and shouldered onto the shaft flange and the collar flange.

The at least one conduit may be further bored through the hub toward a wheel sealed cap or through a bore drilled through the splined shaft, such as having a longitudinal bore portion extending along and at least one radial bore portion communicating the gap and the longitudinal bore. The at least one radial bore can directly interface the at least one opening, in which case the gap may be annulled between the coupling collar and the splined shaft, except for the interface between the at least one opening and the at least one radial bore.

Further optionally the at least one conduit is formed by at least one partially reduced or removed spline ridge or groove, which may be an inner spline ridge or groove of the coupling collar, or an outer spline ridge or groove of the splined shaft.

In accordance with another aspect of the disclosed technique, there is thus provided a method for providing fluid communication between a vehicle fluid pressure source and the tire of a vehicle wheel mounted on a wheel hub and driven by a drive shaft. The method includes providing a pair of mating splined members, one of which is an internally splined coupling collar and the other which is a mating splined shaft configured to fit into the coupling collar, wherein one of the splined members is connected to the drive shaft and the other is connected to the wheel hub. The method further includes boring at least one opening through a side wall of the coupling collar, forming a sealed chamber about the coupling collar, and coupling the sealed chamber in fluid communication with the fluid pressure source and the at least one opening. The method further includes communicating a fluid between the sealed chamber, through the at least one opening, and the tire of the wheel by at least one conduit defined by a gap at an interface between the coupling collar and the splined shaft, running there along, in between.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed technique will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings, wherein like numbers denote like parts, in which:

Figure 1 is an exploded perspective illustration of a vehicle drive axle tire inflation device, constructed and operative in accordance with an embodiment of the invention;

Figure 2 is a perspective view of the device of Figure 1 in its assembled configuration;

Figure 3 is a side view of the device of Figure 1 in its assembled configuration;

Figure 4 is cross sectional side view of the device of Figure 1 in its assembled configuration;

Figures 5A to 5E illustrate cross-sectional views of splined shafts, constructed and operative in accordance with embodiments of the invention, wherein examples of a conduit carved in a ridge or a groove is shown Figures 5B to 5E;

Figures 6A to 6D illustrate side views of the splined shafts of the embodiments of Figures 5A to 5D, correspondingly; Figures 7A to 7C illustrate cross-sectional views of splined couplings, constructed and operative in accordance with embodiments of the invention, wherein examples of a conduit carved in a ridge or a groove is shown Figures 7B and 7C;

Figures 8A and 8B illustrate side views of the splined couplings of the embodiments of Figures 7A and 7B, correspondingly;

Figure 9 is a cross sectional side view of a vehicle drive axle tire inflation device in its assembled configuration, constructed and operative in accordance with an embodiment of the invention; and

Figure 10 is a block diagram of a method for providing fluid communication between a vehicle fluid pressure source and the tire of a vehicle wheel mounted on a wheel hub and driven by a drive shaft, operative in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention overcomes the disadvantages of the prior art by providing a vehicle drive axle tire inflation device for providing fluid communication between a vehicle fluid pressure source and the tire of a vehicle wheel. The device makes use of a pair of coupling members, such as, a pair of splined members: an internally splined coupling collar, and a mating splined shaft configured to fit into the coupling collar. One of the splined members is connected to the wheel hub and the other is connected to the drive shaft, allowing the drive shaft to drive the wheel hub.

The coupling collar includes at least one opening bored through its side wall. A static sealed housing which is disposed about the coupling collar, by means of a rotary joint, forms a sealed chamber about the coupling collar. The sealed chamber is coupled to, and in fluid communication with, at least one opening of the splined collar and the fluid pressure source.

The device features at least one conduit defined by a gap disposed at an interface between the splined collar and the splined shaft and running there along in between the collar and the shaft. The conduit is in fluid communication with the opening of the splined collar and with the tire of the wheel, and is configured to communicate a fluid between the sealed chamber and the tire.

The invention is particularly suitable for implementation in conjunction with vehicles having a separately driven wheel, such as, vehicles having all-wheel-drive, four-by-four wheel drive, six-by-six wheel drive, etc., where each wheel is driven separately and has an independent and separate suspension, typically employing a continuous velocity (CV) joint between the wheel and the drive axle or shaft. A demonstrative example can be given by referencing the system used by High Mobility Multipurpose Wheeled Vehicle (HMMWV) featuring suspension, wheel and hub structure in conjunction with prior art CTIS. However, it is noted that the present invention is primarily directed to address independent suspensions with a CV joint between the drive shaft coming from the differential and the half-shaft leading to the wheel hub, rather than a live axle (wherein the single long shaft can be drilled from a smooth portion thereof all the way to the wheel). In the configuration of a CV joint and a half shaft, it is a problem to introduce air (or other fluid) into the half shaft, as the half shaft is very short, leaving almost no room for installing air insertion mechanisms, and is mostly splined, excluding the possibility of communicating air through a smooth perimeter of the half shaft. The conduit between the splined collar and shaft can be provided by merely reducing or removing entirely at least one spline, either an inner spline of the coupling collar or an outer spline of the splined shaft. If a larger conduit is required, the carving of the conduit can include removal of further material along the collar or the shaft, to create a deep duct carved in place of the conventionally extruding spline. The sealed chamber with its housing and rotary joint can be readily provided by the conventionally available housing of Anti-Lock Breaking Systems (ABS), and used in conjunction with or in place of the ABS speed sensor which is contained therein. Leakage of fluid from the conduit at a gap between the distal end of the collar and the splined shaft can be prevented by interposing an annular seal between the distal end of the collar and a flange of the splined shaft. The flange of the splined shaft is generally disposed at that location as part of the ball bearing of a CV joint, in cases where the splined shaft is the spindle or the outer stub of the CV joint.

Reference is now made to Figures 1 to 4. Figure 1 is an exploded perspective illustration of a vehicle drive axle tire inflation device 100, constructed and operative in accordance with an embodiment of the invention. Figure 2 is a perspective view of device 100 of Figure 1 , in its assembled configuration. Figure 3 is a side view of device 100 of Figure 1 , in its assembled configuration. Figure 4 is cross sectional side view of device 100 of Figure 1 , in its assembled configuration. Device 100 is directed at providing fluid communication between a vehicle fluid pressure source (not shown) and the tire of a vehicle wheel (not shown) which rotates with, and is supported by, wheel hub 102. In addition to hub 102, device 100 includes a drive shaft 106, a pair of splined members 108 (Figures 1 and 4 only) and 1 10, a static sealed housing 1 12, and at least one conduit 1 14 (Figure 4 only). In the embodiment of Figures 1 through 4, splined member 1 08 of wheel hub 102 is in the form of a splined coupling collar 108, and the splined member 1 10 of drive shaft 106 is in the form of a splined shaft 1 10. However, it is noted that the invention is not limited to the illustrated example. The splined shaft and its mating splined collar can be mutually exchanged with each other, respective of their mounting to the functional driving part (drive shaft or hub), namely, being mounted to the counterpart of the driving system. For example, hub 102 can feature a splined member in the form of a splined shaft, while drive shaft 106 can feature a splined member in the form of a mating coupling collar, Drive shaft 106 will drive hub 102 as long as the coupling collar and the mating splined shaft are configured to mesh with each other. Splined shaft 1 10 may be in the form of an outer stub or spindle, a typical example of a short 'half- shaft', and is coupled to a CV joint 1 1 1 of drive shaft 106. Coupling collar 108 includes at least one opening 1 16 bored through its side wall (Figure 4 only). Static sealed housing 1 12 is disposed about coupling collar 108, by means of a rotary joint 1 18 (Figures 1 and 4 only), and forms a sealed chamber 120 (Figure 4 only) about coupling collar 108, which can surround coupling collar 108. Sealed chamber 120 is coupled to, and in fluid communication with, opening 1 16 of coupling collar 1 08. Sealed chamber 120 may be in fluid communication with additional openings that are bored through the sidewall of coupling collar 108 into the area surrounded by sealed chamber 120. Sealed chamber 120 is in fluid communication with the vehicle inflation system fluid pressure source (not shown) through an opening 122. A pipe (not shown) can lead fluid from the fluid pressure source to opening 122. Typically, the fluid pressure source is an air or nitrogen pressure inflation and deflation source, but other fluids can be used in conjunction with the maintenance of adequate pressure in the vehicle tires.

Rotary joint 1 18 may include bearings, such as, tapered rotary bearings 124 that allow static sealed housing 1 12 to remain static with respect to the rotating coupling collar 108. Collar 108 rotates together with splined shaft 1 10, drive shaft 106 and hub 102 when the vehicle is in motion. Rotary joint 1 18 may also feature annular seals 126 (Figure 4) to ensure the sealing of sealed chamber 120 against fluid leakage when bearings 124 and seals 126 are attached to, and surround, coupling collar 108. Annular seals 126 can also be shouldered against flanges 128, 132 with a diameter greater than that of collar 108. Accordingly, splined shaft 1 10 includes a shaft flange 128 which is disposed at the point of engagement with distal-end 130 (Figure 4) of coupling collar 108. Coupling collar 108 includes collar flange 132 (Figure 4) having a diameter greater than that of coupling collar 108. Collar flange 132 is disposed about coupling collar 132 at a distance from distal-end 130 of coupling collar 108, such that static sealed housing 1 12 is positioned about coupling collar 108 between shaft flange 128 and collar flange 132. The outer races 134 of bearings 124 are covered by annular seals 126, and all of them are attached to, surround and are shouldered onto shaft flange 128 and collar flange 132. The inner races 136 of rotary bearings are 124 coupled to coupling collar 108.

The structure described thus far provides sealed fluid communication between the vehicle fluid pressure source and an interfacing area between splined shaft 1 10 and coupling collar 1 18, while rotating, in the area of opening 1 16. The fluid is communicated from the interfacing area to hub 102 (onto which the tire is mounted) by the structure described herein below. Gaps exist between splined shaft 1 10 and coupling collar 1 18 when their mating ridges and grooves are sized at different diameters or widths. These gaps create enclosed cavities that conduct fluid all along the interface between splined shaft 1 10 and coupling collar 1 18. Since opening 1 1 6 encounters at least one such cavity, at least one conduit 1 14 is provided along that splined interface. Accordingly, conduit 1 14 is defined by a gap at an interface between coupling collar 108 and splined shaft 1 10, running there along in between collar 108 and shaft 1 10, in fluid communication with opening 1 16. Conduit 1 14 is in fluid communication with hub 102, on which the tire is mounted, and is therefore configured to communicate a fluid between sealed chamber 120 and the tire.

Conduit 1 14 can be extended with a bore 138 through hub 102 toward a wheel sealed cap 140 and/or piping 142. To further seal possible leakage or loss of fluid from conduit 1 14, a seal 144 may be interposed between distal end 130 of coupling collar 108 and shaft flange 128 at the point of engagement between shaft flange 128 and distal end 130.

In addition to, or alternatively to, conduit 1 14, at least one conduit can optionally be formed or enlarged by at least partially reducing or removing a spline, or other interface portion, forming a deepened groove. Such a reduced or removed spline or groove may be an inner spline or groove of coupling collar 108 or an outer spline or groove of splined shaft 1 10. The cut-out portion of the spline or groove can be limited to the length extending from opening 1 16 to hub 102.

Reference is now made to Figures 5A to 8B, which illustrate a few examples of cut out splined collars and axles, constructed and operative in accordance with embodiments of the invention.

Figures 5A to 5E illustrate cross-sectional views of splined shafts 1 10, constructed and operative in accordance with embodiments of the invention, wherein examples of a conduit 1 14 carved in a ridge or a groove are shown in Figures 5B to 5E. In Figure 5A no cut-out portion is shown, either illustrating a situation in which no gaps exists between coupling collar 108 and splined shaft 1 10, requiring the use of a different splined shaft 1 10, such as, one with a cut-out portion, or a situation in which a gap between coupling collar 108 and splined shaft 1 10 defines a conduit 1 14 in between collar 108 and shaft 1 10 in the vicinity of ridge 1 15. In Figure 5B, the upper portion of ridge 1 15 is cut out to create conduit 1 14. In Figure 5C ridge 1 15 is completely removed to create conduit 1 14. In Figure 5D, in addition to total removal of ridge 1 15, an extra deep groove is carved in its place between adjacent grooves 1 17 to create conduit 1 14. In Figure 5E conduit 1 14 is created by deepening groove 1 17. Figures 6A to 6D illustrate side views of the splined shafts of the embodiments of Figures 5A to 5D, correspondingly.

Figures 7A to 7C illustrate cross-sectional views of splined couplings, constructed and operative in accordance with embodiments of the invention, wherein examples of a conduit carved in a ridge or a groove are shown in Figures 7B and 7C. In Figure 7A, no cut-out portion is shown, either illustrating a situation in which no gaps exists between coupling collar 108 and splined shaft 1 10, requiring the use of a different coupling collar 108, such as, one with a cut-out portion, or a situation in which a gap between coupling collar 108 and splined shaft 1 10 defines a conduit 1 14 in between collar 108 and shaft 1 10 in the vicinity of ridge 121 . In Figure 7B ridge 121 is completely removed to create conduit 1 14. In Figure 7C, the upper portion of ridge 121 is cut out to create conduit 1 14.

Figures 8A and 8B illustrate side views of the splined couplings of the embodiments of Figures 7A and 7B, correspondingly. In addition, opening 1 16 is also shown. Referring to Figure 8A, a gap between coupling collar 108 and splined shaft 1 10 defines a conduit 1 14 in between collar 108 and shaft 1 10, in the vicinity of ridge 121 and denoted by perforated line 1 14, extending all the way along coupling collar 108. Conduit 1 14 is shown to be extended further with bore 138 through hub 102. Since the gap defining conduit 1 14 extends to the other end of coupling collar 108, namely to its distal end 130, in this case seal 144 should be interposed between distal end 130 and shaft flange 128. Referring to Figure 8B, conduit 1 14 is created by the removal of ridge 121 between hub 102 and opening 1 16. However, beyond opening 1 16 there's no need for further removal of ridge 121 , whose tip is shown as being visible through hole 1 16. In this case, if no gap exists between collar 108 and spline shaft 1 10, sealing with seal 144 is not required. Conduit 1 14 is shown to be extended further with bore 138 through hub 102.

Reference is now made to Figure 9, which is a cross sectional side view of a vehicle drive axle tire inflation device 200 in its assembled configuration, constructed and operative in accordance with an embodiment of the invention. Device 200 is similar to device 100 of Figures 1 to 4, wherein like numbers denote like parts, with a variation regarding the fluid communication of the gap defining conduit 1 14 of Figure 4. At least one gap 214 of Figure 9 is in fluid communication with the tire through a bore 238 drilled through splined shaft 1 10. Splined shaft 1 10 and splined collar 108 may feature additional gaps similar to gap 214 along their peripheral interfaced ridges or splines. Some or all of the additional gaps may be connected to bore 238 in a similar manner as gap 214. Bore 238 features a longitudinal bore portion 239, extending along splined shaft 1 10, which is in fluid communication with the tire. Longitudinal bore portion 239 is conveniently drilled along the center axis of splined shaft 1 10 toward the wheel where it can connect to the tire through a wheel hub cap, further piping 240, or other suitable alternatives. Bore 238 further includes at least one radial bore portion 241 communicating gap 214 and longitudinal bore portion 239. If additional gaps similar to gap 214 are dispersed around splined shaft 1 10 to conduct fluid, bore 238 may include additional radial bore portions similar to radial bore portion 241 , such as, one radial bore portion for each additional gap. Radial bore 241 may directly interface opening 1 16, as demonstrated by radial bore 242. In such a case, gap 214 is redundant along most of its length, except for the interface between opening 1 16 and radial bore 242. Accordingly, gap 214 may be annulled between coupling collar 108 and splined shaft 1 10, except for interface 243 between opening 1 16 and radial bore 242. Annulling gap 214 may be achieved either by tightly fitting the mating ridge(s) and groove(s) of splined shaft 1 10 to the corresponding mating ridge(s) and groove(s) of splined collar 108, or by introducing one or more sealing materials to fill gap 214 at least around interface 243. To further seal possible leakage or loss of fluid from conduit 214, a seal 244, such as, an annular O-ring seal, may be interposed between coupling collar 108 and splined shaft 1 10, preferably toward the distal end 130 of coupling collar 108, at a point of engagement between coupling collar 108 and splined shaft 1 10.

Reference is now made to Figure 10, which is a block diagram of a method 900 for providing fluid communication between a vehicle fluid pressure source and the tire of a vehicle wheel that is mounted on a wheel hub and driven by a drive shaft, operative in accordance with a further embodiment of the invention. In procedure 910 of method 900, a couple of mating splined members: an internally splined coupling collar, and a mating splined shaft, configured to fit into the coupling collar, are provided, wherein one of the splined members (the splined shaft or the coupling collar) is connected to the drive shaft and the other to the wheel hub. In reference to Figures 1 through 4, internally splined coupling collar 108 and mating splined shaft 1 10, configured to fit into coupling collar 108, are provided. Splined shaft 1 10 is connected to drive shaft 106 and coupling collar 1 08 is connected to wheel hub 102.

In procedure 920, at least one opening is bored through the side wall of the coupling collar. In reference to Figures 4 and 8B, opening 1 16 is bored through the side wall of coupling collar 108. In procedure 930, a sealed chamber is formed about the coupling collar. In reference to Figure 4, sealed chamber 120 is formed about coupling collar 108.

In procedure 940, the sealed chamber is coupled in fluid communication with the fluid pressure source and the opening bored through the side wall of the coupling collar. In reference to Figures 1 through 4, sealed chamber 120 is coupled in fluid communication with the fluid pressure source via opening 122, and sealed chamber 120 is also coupled in fluid communication with opening 1 16.

In procedure 950, a fluid is communicated between the sealed chamber, through the opening in the side wall of the coupling collar, and the tire of the wheel by at least one conduit. The conduit is defined by a gap at an interface between the coupling collar and the splined shaft running there along in between the collar and the shaft. In reference to Figures 4 to 8B, fluid is communicated between sealed chamber 120, through opening 1 16, and the tire of the wheel by at least one conduit 1 14 defined by a gap at an interface between coupling collar 108 and splined shaft 1 10 running there along in between collar 108 and shaft 1 10.

It will be appreciated by persons skilled in the art that the disclosed technique is not limited to what has been particularly shown and described herein above. While certain embodiments of the disclosed subject matter have been described, so as to enable one of skill in the art to practice the present invention, the preceding description is intended to be exemplary only. It should not be used to limit the scope of the disclosed subject matter, which should be determined by reference to the following claims.

Claims

A vehicle drive axle tire inflation device for providing fluid communication between a vehicle fluid pressure source and the tire of a vehicle wheel, comprising:

a wheel hub comprising a hub splined member;

a drive shaft comprising a mating drive splined member configured to mesh with said hub splined member and drive said wheel hub;

wherein one of said hub splined member and drive splined member comprises a splined shaft and the other comprises a mating splined coupling collar, and said splined coupling collar comprises at least one opening bored through its side wall;

a static sealed housing disposed about said coupling collar, by means of a rotary joint, and forming a sealed chamber about said coupling collar, said sealed chamber being coupled to and in fluid communication with said at least one opening of said coupling collar and with said fluid pressure source; and

at least one conduit defined by a gap at an interface between said coupling collar and said splined shaft running there along in between and being in fluid communication with said opening and with said tire of said wheel and configured to communicate a fluid between said sealed chamber and said tire.

2. The vehicle drive axle tire inflation device as claimed in claim 1 , wherein said splined shaft comprises a shaft flange disposed at the point of engagement with a distal-end of said coupling collar; and wherein said device further comprises a seal interposed between said distal-end of said coupling collar and said shaft flange.

3. The vehicle drive axle tire inflation device as claimed in claim 1 , wherein said drive splined member comprises a spindle which is coupled to a CV joint of a drive axle.

4. The vehicle drive axle tire inflation device as claimed in claim 1 , wherein said drive splined member comprises an outer stub of a CV Joint of a drive axle.

5. The vehicle drive axle tire inflation device as claimed in claim 1 , wherein said rotary joint comprises side bearings and annular seals attached to and surrounding said coupling collar.

6. The vehicle drive axle tire inflation device as claimed in claim 1 , wherein said splined shaft comprises a shaft flange disposed at the point of engagement with a distal-end of said coupling collar; wherein said coupling collar comprises a collar flange having a diameter greater than that of said coupling collar, said collar flange being disposed about said collar at a distance from said distal-end of said coupling collar such that said static sealed housing is positioned about said coupling collar between said shaft flange and said collar flange ; and

wherein said rotary joint comprises side bearings and annular seals attached to, surrounding and shouldered onto said shaft flange and said collar flange.

7. The vehicle drive axle tire inflation device as claimed in claim 1 , wherein said at least one conduit is bored through said hub toward a wheel sealed cap.

8. The vehicle drive axle tire inflation device as claimed in claim 1 , wherein said conduit is in fluid communication with said tire through a bore drilled through said splined shaft.

9. The vehicle drive axle tire inflation device as claimed in claim 8, wherein said bore comprises:

a longitudinal bore portion extending along said splined shaft which is in fluid communication with said tire; and

at least one radial bore portion communicating said gap and said longitudinal bore.

10. The vehicle drive axle tire inflation device as claimed in claim 9, wherein said at least one radial bore directly interfaces said at least one opening.

1 1 . The vehicle drive axle tire inflation device as claimed in claim 10, wherein said gap is annulled between said coupling collar and said splined shaft, except at the interface between said at least one opening and said at least one radial bore.

12. The vehicle drive axle tire inflation device as claimed in claim 1 , wherein said at least one conduit is formed by at least one partially reduced or removed spline ridge or groove.

13. The vehicle drive axle tire inflation device as claimed in claim 12 wherein said at least one partially reduced or removed spline ridge or groove is selected from the list consisting of:

an inner spline ridge or groove of said coupling collar; and an outer spline ridge or groove of said splined shaft.

14. A method for providing fluid communication between a vehicle fluid pressure source and the tire of a vehicle wheel mounted on a wheel hub and driven by a drive shaft, the method comprising the procedures of:

providing a pair of mating splined members, one of which is an internally splined coupling collar and the other of which is a mating splined shaft configured to fit into said coupling collar, wherein one of said splined members is connected to said drive shaft and the other is connected to said wheel hub;

boring at least one opening through a side wall of said coupling collar;

forming a sealed chamber about said coupling collar;

coupling said sealed chamber in fluid communication with said fluid pressure source and said at least one opening; communicating a fluid between said sealed chamber, through said at least one opening, and said tire of said wheel by at least one conduit defined by a gap at an interface between said coupling collar and said splined shaft running there along, in between said coupling collar and said splined shaft.