HK1225351B - Rotary union for tire inflation system - Google Patents

Description

Rotary joints for tire inflation systems

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 61/902,476, entitled “External Rotary Union For Tire Inflation System,” filed on November 11, 2013, which is incorporated herein by reference in its entirety.

Technical Field

The present application relates to an automatic tire inflation system for a vehicle.

Background Art

An automatic tire inflation system can be used to control vehicle tire pressure by adding fluid to the vehicle's tires. The automatic tire inflation system can provide pressurized fluid from a pressurized fluid source to the vehicle's tires to maintain the appropriate tire pressure level regardless of whether the tires are stationary or rotating. The automatic tire inflation system can use multiple regulators, fluid conduits, and rotating fluid connections to provide pressurized fluid to the tires. The automatic tire inflation system can also use one or more valves to control the direction, speed, and volume of fluid flow.

The automatic tire inflation system can provide air to the tire through a conduit located internal to the vehicle structure, such as a rotary joint mounted at the end of a sealing shaft. The automatic tire inflation system can also provide air through a conduit located external to the vehicle structure, such as a rotary joint mounted on a bracket fixed to the vehicle.

The present subject matter provides a rotary joint for an externally wired automatic tire inflation system.

Summary of the Invention

The rotary joint may include: a housing; a shaft rotatably arranged in the housing; a T-shaped body (tee) detachably and non-rotatably connected to the housing; and a tubular component having a first end sealingly arranged in the shaft and a second end sealingly arranged in the T-shaped body. The rotary joint may also include: a radial bushing or bearing arranged around the shaft in the housing; and a thrust bushing or thrust bearing arranged between the first end of the shaft and the inner surface of the housing. The rotary joint may also include: a first annular seal arranged between the shaft and the first end of the tubular component; and a second annular seal arranged between the T-shaped body and the second end of the tubular component. The annular seal may include a lip seal or an O-ring. The tubular component can rotate relative to either or both of the shaft and the T-shaped body.

The rotary joint housing may further include a vent. The rotary joint may further include a seal that closes the vent and is configured to allow pressurized fluid to escape the rotary joint if one or both of the first annular seal and the second annular seal fail. The rotary joint may further include an annular seal disposed within the housing around the shaft adjacent to the radial bushing or bearing, and a shield disposed around the shaft adjacent to the housing to shield the annular seal from environmental hazards. The rotary joint may further include at least one hose fitting.

The rotary joint may include: a housing; a shaft rotatably disposed within the housing; and a tube having a first end sealingly disposed within the shaft and a second end sealingly connected to the housing, the tube rotatable relative to one or both of the shaft and the housing.

A vehicle tire inflation system may include a fluid pressure source and a swivel mounted on a vehicle fairing in sealed fluid communication with the pressure source and one or more vehicle tires.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an embodiment of a vehicle having an automatic tire inflation system.

FIG. 2 illustrates an embodiment of an automatic tire inflation system including an external rotary joint.

FIG3 shows an embodiment of a rotary fluid connection mounted on a vehicle fairing.

FIG. 4A shows a cross-sectional view of an embodiment of a rotary joint, and FIG. 4B shows an external view thereof.

FIG5 shows an embodiment of a rotary joint and a T-piece.

FIG6 shows an embodiment of a rotary fluid connection.

FIG. 7 shows an embodiment of a rotary joint fluid connection.

DETAILED DESCRIPTION

As shown in FIG1 , vehicle 100 may include a truck 102 and a trailer 104. Truck 102 may include one or more drive axles 106 as part of the vehicle's powertrain. Truck 102 may also include a steering axle (not shown in detail) having a pivotable spindle that provides steering capability for vehicle 100. Trailer 104 may include one or more fixed axles (not shown). Each axle may have one or more wheels 108 mounted thereon. Pneumatic tires 110 may be mounted on each wheel 108.

The vehicle 100 can be provided with an automatic tire inflation system (ATIS) (e.g., shown in more detail in FIG. 2 ) that can use pressurized fluid from the vehicle's fluid brake system and/or some other source of pressurized air or other gas to maintain the appropriate fluid pressure in the tires. The ATIS can be used to control the fluid pressure in one or more tires 110 mounted on a steering axle (not shown), a drive axle 106, and/or a trailer axle (not shown). The ATIS can include one or more hoses 112 in fluid communication with each tire 110 for communicating pressurized fluid from a pressure source to and from the one or more tires 110. The pressurized fluid can include air, pure nitrogen, some other inert gas, or any mixture thereof.

The ATIS may provide fluid to the hose 112 through a swivel 113 mounted on a bracket 115 secured to the wheel 108. The swivel 113 may receive the fluid through one or more conduits 117 mounted externally to the vehicle.

FIG2 shows in more detail several embodiments of an example automatic tire inflation system. A trailer 200 may include two axles 202, 204. Some trailers 200 may have dual tires 206, 208 mounted on wheels 209, 211 at each end of the axles 202, 204, as seen with respect to axle 202. Other trailers 200 may have single tires 210, such as super single tires or wide base tires, mounted at each end of the axles 202, 204, as seen with respect to axle 204. Wide base tires may include tires manufactured by, for example, Michelin, Toyo, Goodyear, Bridgestone, and other tire manufacturers. The ATIS typically may include an air pressure regulator (not shown), which may be mounted in a control box 214.

The ATIS can include one or more rotating fluid connections or swivels 216, 218 mounted on a bracket 226. Bracket 226 can be connected to wheels 209, 211 and can rotate with wheels 209, 211. An air pressure regulator can receive pressurized air from an air pressure source 220 via conduit 212. Air pressure source 220 can include, for example, a vehicle air brake system air supply. Pressurized fluid can flow from the fluid pressure regulator through conduit 222 to hoses 228, 230. From there, the fluid can flow through hoses 228, 230 to rotary connections 216, 218 to hoses 224, 232 to valves 219, 221, 223, respectively, which are connected to tires 208, 210, 206, respectively.

Hoses 228, 230 may comprise flexible conduits, each of which may be threadedly attached to manifold 227 at one end and may be threadedly attached to swivel connectors 216 and 218 at their respective other ends. The ends of the hoses, which may be attached to manifold 227, may include one-way check valves, such as Schraeder valves, that allow fluid to flow toward the tires but not in the opposite direction. Hoses 228, 230 may also comprise a metal tubular sheath (not shown) disposed around the flexible conduits to prevent wear. The metal tubular sheath may be crimped onto the flexible conduits at one end to substantially prevent the flexible conduits from translating into the sheath. A strain relief device 231 may be disposed around each hose 228, 230 to prevent the hoses from becoming tangled. Manifold 227 and hoses 228, 230 may be disposed about the exterior of the vehicle. When connected to the manifold 227 and the swivel connectors 216, 218, the hoses 228, 230 may be, for example, approximately 1-2 inches away from the tire.

FIG3 illustrates one embodiment of a swivel connector 216 mounted to a bracket 226 using any suitable fasteners, such as bolts 314 and 316. Bracket 226 can be mounted to a wheel or fairing using any suitable fasteners, such as bolts 310 and 312. The swivel connector 216 can include a swivel joint 300, a T-piece 302 coupled to the swivel joint, and a hose connector 304 coupled to the swivel joint. The T-piece 302 and hose connector 304 can be coupled to the swivel joint using threads or any other suitable means. Tire pressurization fluid can flow from pressure source 220 through hose connector 304 and into the swivel joint. The fluid can flow from the swivel joint through T-piece 302 and from the T-piece to the tire through a hose (not shown), which is connected from the tire to T-pieces 308 and 306.

Figures 4A and 4B illustrate the rotary joint of Figure 3 in detail. As can be seen in the cross-sectional view of Figure 4A and the exterior view of Figure 4B, the rotary joint can include a shaft 400 disposed within a housing 402. A radial bushing 404 can be disposed between the shaft 400 and the housing 402. The bushing 404 can include an oil-impregnated material such as a porous bronze alloy, or PTFE, nylon, or any other suitable, wear-resistant material with a relatively low coefficient of friction. In other embodiments, rollers or ball bearings can be used in place of the bushing. More clearly, the housing 402 can include a lip 406 that can help retain the bushing 404 within the housing 402. In some embodiments, an annular seal 408 can be disposed between the lip 406 and the bushing 404. In some embodiments, the annular seal 408 can include a lip seal.

In some embodiments, the shaft 400 can be constrained from translating into the bushing 404 (or bearing) by providing a retaining ring 410 disposed around the shaft 400. A washer 412 can be disposed between the bushing 404 and the retaining ring 410.

In some embodiments, the end cap 414 can be connected to the housing 402, such as by threads. In other embodiments, the housing 402 and the end cap 414 can comprise a unitary piece. A splash shield 416 can be positioned around the shaft 400 against the end of the lip 406 of the housing 402 to shield the annular seal 408 from debris, high-volume or high-velocity liquid flow, and other environmental hazards. In some embodiments, a gasket 416 can be positioned between the splash shield 416 and the end of the housing 402. A retaining ring 418 can be used to prevent the splash shield 416 from sliding off the shaft 400.

In some embodiments, shaft 400 can be generally cylindrical and can be machined or molded, for example, from steel or polycarbonate. In some embodiments, grooves 420 and 422 can be provided to enable retaining rings 410 and 418 to be disposed circumferentially around shaft 400. A groove 424 can be provided in the interior dimensions of shaft 400 in which an annular seal 426 (e.g., an O-ring) can be disposed.

FIG5 illustrates an embodiment of a T-shaped member 302. In some embodiments, the T-shaped member 302 can include a T-shaped body 502 and an elongated tubular member 504, preferably metal, having a first end 506 and a second end 508, more particularly as described in U.S. Patent No. 6,698,482, entitled "Rotary Air Connection with Bearing for Tire Inflation System," which is incorporated herein by reference in its entirety. In other embodiments, the T-shaped member 302 can include a rotary air connection, such as described in U.S. Patent No. 5,769,979, entitled "Rotary Air Connection for Tire Inflation System," which is incorporated herein by reference in its entirety.

The first end 506 of the tubular member 504 is sealingly connected to the T-body 502 via an annular seal 510. The seal 510 can be any suitable dynamic seal that allows axial and rotational movement of the end 506, such as a lip seal or an O-ring seal, and is held in place by a telescoping cap 512. The T-body 502 can be threadedly connected to the end cap 414, which is used to connect to a tire at the end of the shaft. Thus, the T-body 502 can be removably and non-rotatably connected to the end cap 414. When the T-body 502 is threadedly connected to the end cap 414, the end 508 of the tubular member 504 extends into and sealingly engages the annular seal 426, thereby compensating for any misalignment or translation of the shaft 400 within the housing 402. That is, the second end 508 can coaxially extend through the passage 514 and can move longitudinally and rotationally therein, while sealingly engaging the annular seal 426. Passageway 514 is in communication with a fluid supply conduit (not shown). A first resilient annular seal 426 is supported within and surrounds passageway 514. The annular seal may comprise any suitable seal, such as a lip seal or an O-ring, and may comprise any suitable material, such as nitrile, silicone, or rubber. Thus, tire pressurizing fluid may circulate through shaft passageway 514, tubular member 504, and T-body 502 (via channel 522). The tubular member may be rigid or flexible, or may include both rigid and flexible portions.

The end 506 of the tubular member 504 can include a shoulder 516, which can be a male flange in commercial applications. A bearing 518 can cooperate with the shoulder 516 to limit longitudinal or axial movement of the tubular member 504 and prevent the shoulder 516 from engaging an internal flange 520 on the air connector or T-body 502.

In some embodiments, the end cap 414 may be omitted and the T-piece 302 may be directly connected to the housing 300 , such as by threads.

In some embodiments, bracket 226 can be mounted on a vehicle fairing, which should be understood to include any aerodynamic vehicle fairing, skirt, trim, fender, aerodynamic wheel cover, or a cover arranged on or covering the wheel end, as shown in the embodiment of Figure 6. Such a fairing 600 can be provided, for example, to cover a portion of tire 208 in order to improve aerodynamic efficiency, protect the wheel end, or for decorative purposes. Fairing 600 can cover the outside of all or part of tire 208 mounted on a drive shaft, steering shaft, or trailer axle. Of course, any other suitable external ATIS or rotary joint can be mounted on fairing 600. In the embodiment of Figure 6, bracket 226 can be non-rotatably mounted on fairing 600. Any other suitable mounting structure can be used to mount the external rotary joint on the side of the fairing facing the wheel, rather than just the bracket shown in Figure 3. Externally disposed fluid conduits (eg, one or more of conduits 222 , 228 , and 230 of FIG. 2 ) may similarly be mounted on the fairing to provide fluid communication with the rotary connection 216 .

The rotary connector 216 can accommodate tire rotation in a variety of ways. When the bracket 216 is mounted on a wheel, the bracket will rotate with the wheel. Consequently, the housing, end caps, and T-piece 302 can also rotate with the wheel. The rotary joint shaft can remain substantially rotationally stationary. Referring to the embodiment of FIG. 5 , the tubular member 504 can rotate within either or both of the annular sealing members 510 and 426. One or the other of the sealing members 510 and 426 can secure the tubular member 504 from rotation.

In the embodiment of FIG. 6 , bracket 216 can be mounted on fairing 600 . In such an embodiment, hose connector T-piece 302 can include one or more hose attachment points and rotate with the wheel. In the embodiment of FIG. 6 , dual tires 206 and 208 are visible; therefore, two hose attachment points 301A and 301B can be provided in hose connector 302 to enable sealed fluid communication with tires 206 and 208 via hose 232 . A wider single tire may only require a single hose attachment point in hose connector T-piece 302 . In other words, T-piece 302 can include one or more hose attachment fittings. Thus, the housing, end cap, and T-piece 302 can also remain rotationally stationary. As the wheel rotates, the swivel shaft and hose connector 302 can rotate. Referring to the embodiment of FIG. 5 , tubular member 504 can rotate within either or both of annular sealing members 510 and 426 .

FIG7 illustrates another embodiment of a rotary joint 216. A shaft 700 can be rotatably disposed within a housing 702. A thrust washer 706 can be disposed within the housing 702 between a first end 704 of the shaft 700 and a shoulder 708. The thrust washer 706 can comprise an oil-impregnated material such as a porous bronze alloy, or PTFE, nylon, or any other suitable wear-resistant material having a relatively low coefficient of friction. In other embodiments, a thrust roller or a ball bearing can be used in place of the thrust washer 706.

A radial bushing 710 can be disposed around the shaft 700 in the housing 702. The radial bushing 710 can include an oil-impregnated material such as a porous bronze alloy, or PTFE, nylon, or any other suitable, wear-resistant material with a relatively low coefficient of friction. In other embodiments, rollers or ball bearings can be used in place of the radial bushing. A snap ring or retainer clip 712 can be disposed around the inner diameter of the housing 702 to retain the shaft 700 and radial bushing 710 within the housing 702. In some embodiments, an annular seal 714 (e.g., a lip seal) can be disposed between the inner diameter of the housing 702 and the outer diameter of the shaft 700 to provide a substantially sealed interface between the housing 702 and the shaft 700. A splash shield 730 can be disposed around the shaft 700 against the housing 702 and can be held in place by a retaining ring 716 disposed around the outer diameter of the shaft 700.

Housing 702 may be provided with one or more vent holes 718 to allow pressurized air to escape from rotary joint 216 in the event of a seal failure (e.g., failure of annular seal 510 (shown in FIG. 5 ) or annular seals 426 (shown in FIG. 5 ) or 726 (shown in FIG. 7 )). An annular seal 720 (e.g., an O-ring having a square cross-section) may be resiliently disposed about the housing over vent hole 718 to prevent air, moisture, or debris from entering the rotary joint through vent hole 718. Any other suitable seal may be used to seal the vent hole from such entry, such as a check valve, a duckbill valve, a flexible diaphragm, or a rubber band.

In some embodiments, a hose fitting 722 can be threadedly coupled to the shaft 700 to better attach a fluid conduit carrying pressurized fluid from the pressure source 220. A T-piece (not shown), such as the T-piece 302 of FIG5 , can be threadedly coupled to the housing 702 at the outlet 724. The tubular portion of the T-piece (e.g., 504) can be disposed within an annular seal 726 disposed within the fluid channel 728, as described in conjunction with FIG5 .

In yet another embodiment, the housing 702 may include a T-shaped body 502, an annular seal 510, and a tubular member 504 (see the components shown in FIG. 5 ). That is, the T-shaped body need not be separate from the housing. Other components disclosed herein may include separate parts or may include one or more integrally manufactured pieces.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and modifications may be made without departing from the present invention as defined by the appended claims. Moreover, the scope of this application is not limited to the particular embodiments of the processes, machines, manufactures, components or substances, devices, methods and steps described in the specification. As will be readily apparent from the present invention, processes, machines, manufactures, components of substances, devices, methods and steps currently existing or later developed that perform substantially the same functions or obtain substantially the same results as the corresponding embodiments described herein may also be used. For example, although the disclosed apparatus, systems and methods may be described with reference to manually or manually actuated pressure reducing valves, electric valves or other automatic electronic or mechanical valves may be used to achieve a relatively rapid reduction in fluid pressure. Therefore, the appended claims will include within their scope such processes, machines, manufactures, components of substances, devices, methods, systems and steps.

Claims (20)

1. A rotary joint configured for arrangement on a vehicle having axles and wheel ends, the rotary joint configured for arrangement outside the wheel ends to provide pressurized fluid from a fluid source of the vehicle to one or more tires of the vehicle at the wheel ends, the rotary joint comprising: case; A rotary joint shaft, rotatably arranged within a housing, is configured for fluid communication with a pressure source external to the shaft and wheel ends; A T-shaped body, detachably and non-rotatably connected to a housing, having fluid channels formed therein for delivering pressurized fluid to one or more vehicle tires; and A tubular component configured to transmit pressurized fluid between a rotary joint shaft and a T-shaped body, the tubular component having a first end disposed in the rotary joint shaft and a second end disposed in the T-shaped body. A first annular seal is disposed between the rotary joint shaft and a first end of the tubular component; and A second annular seal is disposed between the second end of the T-shaped body and the tubular component. 2. The rotary joint according to claim 1, further comprising: A radial bushing or radial bearing, arranged within the housing surrounding the rotary joint shaft; and A thrust bushing or thrust bearing is arranged between the first end of the rotary joint shaft and the inner surface of the housing. 3. The rotary joint according to claim 1, wherein the housing further includes a vent. 4. The rotary joint according to claim 1, wherein: the first annular seal and the second annular seal each comprise an O-ring or a lip seal. 5. The rotary joint according to claim 3, further comprising: a seal that closes the vent and is configured to allow pressurized fluid to escape from the rotary joint when one or both of the first annular seal and the second annular seal fail. 6. The rotary joint according to claim 2, further comprising: An annular seal, which is arranged within the housing adjacent to a radial bushing or bearing surrounding the rotary joint shaft; and A shielding element is arranged around the rotary joint shaft adjacent to the housing to shield the annular seal from environmental hazards. 7. The rotary joint according to claim 2, wherein the T-shaped body further comprises at least one hose fitting. 8. The rotary joint according to claim 1, wherein: the tubular component is rotatable relative to either or both of the rotary joint shaft and the T-shaped body. 9. The rotary joint according to claim 7, wherein the T-shaped body further comprises two T-shaped fittings. 10. The rotary joint of claim 1, wherein: the rotary joint is configured to be mounted to the wheel end such that when sealed to the wheel end, the T-shaped body can rotate together with one or more tires. 11. The rotary joint of claim 1, wherein: the rotary joint is configured to be mounted to a vehicle fairing such that when sealed to the vehicle fairing, the T-shaped body can rotate together with one or more tires. 12. The rotary joint according to claim 1, wherein the T-shaped body can be threadedly connected to the housing. 13. A rotary joint configured for arrangement on a vehicle having axles and wheel ends, the rotary joint configured for arrangement outside the wheel ends to provide pressurized fluid from a fluid source of the vehicle to one or more tires of the vehicle at the wheel ends, the rotary joint comprising: A housing having fluid channels formed therein for delivering pressurized fluid to the tires of one or more vehicles; A rotary joint shaft, rotatably arranged within a housing, configured for fluid communication with an external pressure source at the shaft and wheel ends; and A tube configured to transmit pressurized fluid between a rotary joint shaft and a housing, the tube having a first end sealed within the rotary joint shaft and a second end sealed to the housing, the tube being rotatable relative to either or both of the rotary joint shaft and the housing. A first annular seal is disposed between the rotary joint shaft and the first end of the tube; and A second annular seal is disposed between the housing and the second end of the tube. 14. The rotary joint according to claim 13, further comprising: A radial bushing or radial bearing, arranged within the housing surrounding the rotary joint shaft; and A thrust bushing or thrust bearing is arranged between the first end of the rotary joint shaft and the inner surface of the housing. 15. The rotary joint according to claim 13, wherein the housing further includes a vent. 16. The rotary joint according to claim 13, wherein: the first annular seal and the second annular seal each comprise an O-ring or a lip seal. 17. The rotary joint of claim 15, further comprising: a seal that closes the vent and is configured to allow pressurized fluid to escape from the rotary joint when one or both of the first annular seal and the second annular seal fail. 18. The rotary joint according to claim 14, further comprising: An annular seal, which is arranged within the housing adjacent to a radial bushing or bearing surrounding the rotary joint shaft; and A shielding element is arranged around the rotary joint shaft adjacent to the housing to shield the annular seal from environmental hazards. 19. The rotary joint according to claim 14, wherein the T-shaped body further comprises at least one hose fitting. 20. The rotary joint according to claim 19, wherein the T-shaped body further comprises two T-shaped fittings.