HK1226031B - Rotary union for automatic tire inflation system - Google Patents

Description

Rotary joints for automatic tire inflation systems

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Serial No. 61/894,653, filed on October 23, 2013. The entire disclosure of the foregoing application is incorporated herein by reference.

Technical Field

The disclosed methods and apparatus generally relate to vehicle tire inflation systems.

Background Art

There is a need for a method and apparatus for an improved rotary joint for a vehicle tire inflation system.

Summary of the Invention

A rotary joint may include: a stator having a first fluid passage disposed therethrough; a first annular seal disposed within the first fluid passage; a rotor body having a second fluid passage disposed therethrough, the rotor body being configured to be removably mounted to the interior of a hubcap, the hubcap having a third fluid passage disposed therein such that the second fluid passage and the third fluid passage are in sealed fluid communication when the rotor body is mounted thereto; a second annular seal disposed within the second fluid passage; and a tube sealingly disposed within the first and second annular seals. A rotary joint may include: a stator; and a rotor assembly including a rotor body and a tube sealingly disposed therein, wherein the tube is sealingly coupled to the stator, wherein the rotor assembly is configured to be removably mounted to the interior of the hubcap. A rotary joint may include: a stator; and a rotor assembly including a hubcap and a tube sealingly and rotatably disposed within the interior of the hubcap, wherein the tube is sealingly and rotatably coupled to the stator. A rotary joint may include: a stator; and a tube sealingly and non-rotatably disposed within an interior of a hubcap, wherein the tube is sealingly and rotatably coupled to the stator.

A vehicle tire inflation system may include: a fluid source; and a rotary joint in sealed fluid communication with the fluid source and configured to be removably mounted to an interior of a hubcap. A vehicle tire inflation system may include: a fluid source; and a hubcap, the hubcap including a first fluid passage and a rotary joint disposed within the interior of the hubcap and in sealed fluid communication with the first fluid passage and with the fluid source, the rotary joint including a tube having an end disposed within the hubcap; and an annular seal disposed between the tube and the hubcap to form a sealed interface between the tube and the hubcap. A vehicle tire inflation system may include: a fluid source; a stator including an annular seal, the stator being in sealed fluid communication with the fluid source; a hubcap including a first fluid passage; a tube non-rotatably mounted to the hubcap, the tube having a first end and a second end, the first end being in sealed fluid communication with the first fluid passage, the second end being sealingly and rotatably disposed within the annular seal; and a first fluid conduit having a first end and a second end, the first end being in sealed fluid communication with a first vehicle tire, the second end being in sealed fluid communication with the first fluid passage.

A hubcap having a fluid passageway may include: an annular seal disposed in the fluid passageway; and a tube located within an interior of the hubcap and having an end sealingly and rotatably disposed within the annular seal. A hubcap having a fluid passageway may include a tube extending into the interior of the hubcap and in sealed fluid communication with the fluid passageway, the tube being secured against rotation relative to the hubcap.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of a rotary joint for a tire inflation system.

FIG. 2 shows a detailed view of the rotary joint of the embodiment of FIG. 1 .

FIG3 shows a detailed view of an embodiment of a rotary joint.

FIG. 4 shows a perspective view of the embodiment of FIG. 1 .

FIG. 5 shows an “exploded” view of FIG. 4 .

FIG. 6 shows a detailed view of an embodiment of an exemplary hubcap.

FIG. 7 shows a stator having a fluid conduit connected thereto for sealed connection to a fluid pressure source.

FIG. 8 illustrates an embodiment of a rotary joint for a tire inflation system.

DETAILED DESCRIPTION

FIG1 shows an exemplary rotary joint 10 disposed at the wheel end of a vehicle, such as a commercial truck or trailer. In the example of FIG1 , a hollow trailer axle 12 can have a hub 14 mounted thereto as is known in the art. The hollow axle 12 can be sealed at each end 12 a by a plug 16, such as an extruded plug. The rotary joint 10 can include a stator 18, which can be sealingly mounted in the plug 16, and a rotor assembly 20. The rotor assembly 20 can include a tube 22 having a length sufficient to extend into the stator 18. The rotor assembly 20 can be mounted to a hub cap 26. Specifically, the rotor assembly 20 can be mounted to the interior of the hub cap so that the rotary joint 10 is completely contained within the space formed by the hub cap and the wheel end.

The hub cap 26 may include one or more fluid passages 24 radiating from a center through which a fluid, such as pressurized air, may be communicated. The hub cap 26 may be sealingly mounted to the hub 14 via lug nuts 28. The hub cap 26 may be sealed at the hub periphery 30 by a gasket 32, a sight glass 34, and a retaining ring 36. The sight glass 34 may include a plug 38. In other embodiments, the plug 38 may be mounted in the retaining ring 36 and extend through the sight glass 34. In some embodiments, the plug 38 may include a pressure relief valve or opening to relieve fluid pressure that may accumulate in the hub cap 26. Such a plug 38 may be, for example, a Sentinel ^™ ESP plug or a Sentinel ^™ ESP filter vent manufactured by Stemco.

When assembled with the wheel end, the tube 22 of the rotor assembly 20 can sealingly extend into the stator 18. The rotor assembly 20 can be sealingly mounted to the hub cap 26, such as by NPT threads or straight threads or an O-ring raised seal. The hub cap 26 can be mounted to the hub 14. The sight glass assembly 50 can be sealingly mounted to the hub cap 26 by, for example, screws (not shown).

The rotary joint 10 can be used with a tire inflation system, such as an automatic tire inflation system manufactured by Pressure Systems International, Inc. Of course, the rotary joint disclosed herein can be used with any other suitable tire inflation system (for sealed or unsealed axles, solid or hollow, or trailer, drive, or steer axles). In the embodiment shown in FIG1 , a pressurized fluid (which can be, for example, air, nitrogen, and/or other tire pressurizing fluid) can flow from a pressure source 40 through a conduit 42 to a pressure regulator 44, which can adjust the pressure of the fluid to a pressure suitable for tire inflation, such as 110 psi. From the pressure regulator 44, the fluid can flow through a conduit 46 to the axle 12. The fluid can flow through the axle 12 to the stator 18. A filter 48 can remove particles from the fluid before it enters the stator 18. The fluid can flow through the stator 18 into the tube 22 of the rotor assembly 20. The fluid can flow from the rotor assembly 20 through the fluid passage 24 to a hose 52, which is connected to the hubcap via a fitting 54. The hose 52 can be connected to a tire valve 56 to allow the fluid to flow to the tire (not shown). Thus, the rotary joint 10 can allow pressurized fluid to flow from the pressure source 40 to the tire regardless of whether the vehicle is in motion. The hubcap 26 and a portion of the rotary joint assembly 20 can rotate with the vehicle tire (not shown), which can be mounted to a wheel (not shown), which is mounted to the hub 14.

FIG2 provides a more detailed view of the exemplary rotary joint 10 of FIG2 . As can be seen in the embodiment of FIG2 , the stator 18 can include a head 200 and a stator tube 202 that form a stator fluid passage 204. A filter 48 can be mounted at one end of the stator tube 202 to remove larger debris particles from the pressurized fluid. An annular seal 206 can be disposed in a groove around the diameter of the fluid passage 204. The annular seal 206 can be an O-ring, a lip seal, or any other suitable seal configuration, and can include a variety of materials, such as rubber, silicone, nylon, oil-containing bearing alloys, or graphite. The annular seal 206 can be configured to seal the tube 22 within the stator 18 when the tube 22 is inserted into the stator 18.

In other embodiments, the stator can include a port drilled into a solid axle, such as a solid trailer axle or a truck steering axle. In other embodiments such as those with unsealed axles, the stator can be installed in the axle end without sealing and sealed to the fluid conduit 46 (Fig. 7). In the embodiment of Fig. 7, the stator 800 can be installed at the end of a hollow or drilled axle (not shown), such as by squeezing a plug 802 or other suitable sealing or non-sealing plugs or supports, or for example by friction fit or threads. The fluid conduit 46 can be sealed to a fluid pressure source such as by a Prestolok ^™ fitting 804. The stator 800 can define an opening 806 into which a rotor assembly tube (not shown) can be sealed. This sealed insertion can be achieved, for example, by an annular sealing member (not shown) arranged around the inner diameter of the stator opening 806 in a manner similar to that shown in Fig. 2.

As can be further seen in FIG. 2 , the rotor assembly 20 can include a tube 22 and a rotor body 208. The rotor body 208 can include a threaded portion 208a that can be used to mount the rotor assembly to a hub cap having matching threads. In the embodiment of FIG. 2 , the threaded portion 208 is shown as an NPT thread. However, straight threads and other threads can also be used. Of course, any other suitable mounting means can be provided, such as a key and slot, a friction fit, an adhesive, a crimp, etc. The rotor body 208 can include a fluid chamber 209. The tube 22 can be assembled to the rotor body 208 via a telescoping cover 212. The telescoping cover 212 can be mounted to the rotor body 208 by any suitable means, such as a friction fit, threads, an adhesive, a crimp, etc. The tube 22 can include a flared end 210 that can be disposed within the fluid chamber 209. The flared end 210 can prevent the tube 22 from sliding out of the telescoping cover 212. A bearing 214 can be disposed between a lip 216 of the rotor body 208 and the flared end 210 of the tube 22. The bearing can comprise any suitable material, such as graphite, nylon, an oil-retaining bearing alloy, Delrin, brass, or any other material suitable for reducing wear or friction between the tube 22 and the rotor body 208. The tube 22 can be sealed to the rotor body 208 by an annular seal 218. The annular seal 218 can be an O-ring, a lip seal, or any other suitable seal configuration and can comprise a variety of materials, such as rubber, silicone, nylon, an oil-retaining bearing alloy, or graphite. The tube 22 can rotate within the annular seal 206 and/or the annular seal 208.

The tube 22 may comprise any suitable material or combination of materials and may be rigid and/or flexible. For example, the tube 22 may comprise steel, brass, nylon, polycarbonate, acrylic, rubber, or any combination thereof. For example, the flared end 210 of the tube 22 may comprise a steel tubular portion, and the stator end 220 may comprise a nylon tubular portion, and the nylon and steel portions may be coupled by any suitable means (such as compression rings, threads, adhesives, friction fits, Presto-Lok fittings, etc.). The rigid tube may pivot within and/or translate through either or both of the annular seals 206 and 208 to accommodate misalignment between the hub and the shaft (e.g., possibly caused by bearing clearance). A fully or partially flexible tube may accommodate such misalignment by bending. In some embodiments, the friction between the annular seal 206 and the tube may be different from the friction between the annular seal 208 and the hub, thereby allowing the tube to rotate at a speed different from that of the hub cap. In some embodiments, the friction between annular seals 206 or 208 may be sufficient to prevent the tube from rotating within the seal, which may cause the tube to rotate as fast as the hubcap (i.e., the tube will not rotate relative to the hubcap), or not rotate at all (i.e., the tube will be stationary relative to the hubcap).

In further embodiments, one or more additional annular seals may be disposed in stator 200, such as adjacent annular seal 206. Similarly, one or more additional annular seals may be disposed in rotor body 208, such as adjacent annular seal 218.

FIG3 shows an embodiment of a rotor assembly in which a hubcap 26 is configured to serve as the rotor body. The hubcap 26 may include a fluid chamber 250 from which the fluid passages 24 radiate. The tube 22 may be disposed in the fluid chamber 250 and retained by a telescoping cover 212 mounted to the hubcap 26. An annular seal 218 may provide a sealed interface between the tube 22 and the hubcap 26. A bearing 214 may be disposed between the flared end 220 of the tube and the hubcap 26. Pressurized fluid may flow from the stator 18 through the tube 22 and into the hubcap fluid chamber 250, and from there to one or more fluid passages 24.

FIG4 shows an embodiment of a rotor assembly 20 (such as the embodiment of FIG2 ) mounted to a hub cap 26. A fluid passage 24 (not shown) may be provided through the radial projection 400. The rotor body 208 may be threadably mounted to the hub cap. The sight glass 34 may have a plug or vent 38 mounted thereto. FIG5 shows an exemplary threaded port 600 into which a fluid chamber 602 of the rotor assembly 20 may be threadably mounted, and also shows the rotor assembly 20 of FIG4 removed or "disassembled" from the hub cap 26.

6 shows hub cap 26 and its various components, including retaining ring 36 , sight glass 34 , plug or vent 38 , screws 700 used to mount the retaining ring to hub cap 26 , and hose fitting 54 .

As can be seen in FIG. 8 , tubular extension 90 can be removably mounted to hubcap 26 . Because of this mounting, tubular extension 90 can be substantially fixed against rotation relative to hubcap 26 . In some embodiments, tubular extension 90 can include a threaded portion 91 for threadably engaging hubcap 26 . As described above, tubular extension 90 can include a tube 92 having a flexible portion 93 and a rigid portion 94 . In other embodiments, tubular extension 90 can include a fully flexible tube or a fully rigid tube. In still other embodiments, the flexible and rigid portions of tube 92 can be reversed: portion 93 can be rigid and portion 94 can be flexible. Portion 93 of tube 92 can be inserted into stator 16 , such as the stator described in conjunction with FIG. 2 . In such embodiments, a rotary joint sealing interface can be formed by rigid portion 93 and an annular seal, such as O-ring 206 . Depending on the configuration of tube 92 , tube 92 can translate, rotate, and/or pivot within annular seal 206 in the stator.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and variations can be made herein without departing from the present invention as defined by the appended claims. In addition, the scope of the application is not intended to be limited to the particular embodiments of the processes, machines, manufactures, compositions, or substances, devices, methods and steps described in this specification. As will be readily understood from this disclosure, processes, machines, manufactures, compositions, devices, methods or steps currently existing or to be developed later that perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein may be used. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions, devices, methods or steps within their scope.

Claims (14)

1. A rotary joint, the rotary joint comprising: A stator, the stator being disposed in the axle of a vehicle, the stator having a first fluid passage disposed through it; A first annular seal is disposed within the first fluid channel; The rotor body has a through-flow second fluid passage, the rotor body is configured to be removably mounted into the interior of a hub for a vehicle hub, the hub being able to release internal pressure to the atmosphere and having a third fluid passage arranged in the hub such that when the rotor body is mounted into the interior of the hub, the second fluid passage and the third fluid passage are in sealed fluid communication. A second annular seal is disposed in the second fluid channel; and A tube, configured to be hermetically and pivotally arranged in a first annular seal and configured to be hermetically and pivotally arranged in a second annular seal to accommodate misalignment between the vehicle's hub and the vehicle's axle, the tube being further translatably arranged in the first annular seal such that when the hubcap is removed from the vehicle's hub, the tube can be translated out of and disengaged from the first annular seal, and the tube is further rotatable in either or both of the first and second annular seals. 2. The rotary joint according to claim 1, wherein the tube is rigid. 3. The rotary joint according to claim 1, wherein the tube is flexible. 4. The rotary joint according to claim 1, wherein the tube comprises a flexible portion and a rigid portion. 5. The rotary joint according to claim 1, wherein the first annular seal comprises an O-ring, and the second annular seal comprises a lip seal. 6. The rotary joint according to claim 1, wherein the first annular seal comprises a lip seal, and the second annular seal comprises an O-ring. 7. The rotary joint according to claim 1, wherein the first annular seal and the second annular seal each include an O-ring. 8. The rotary joint according to claim 1 further includes a telescopic cover, the telescopic cover being disposed around the tube and engaging with the rotor body to retain the tube within the rotor body. 9. The rotary joint according to claim 8, wherein one end of the tube is widened to prevent that end from translating through the second annular seal and the telescopic cap. 10. The rotary joint of claim 9 further includes a bearing disposed between an end of the tube and the rotor body, the bearing including a fluid passage to allow fluid to flow from the tube to the rotor body. 11. The rotary joint according to claim 1, wherein the rotor body can be threadedly mounted into the interior of the hub cover. 12. A rotary joint, the rotary joint comprising: A rotor assembly configured to be removably mounted inside a hubcap configured to be mounted on a vehicle hub and capable of releasing internal pressure to the atmosphere, the rotor assembly including a rotor body and a tube hermetically and pivotally disposed within the rotor body, wherein the tube is hermetically and pivotally coupled to a stator to accommodate misalignment between the vehicle hub and the vehicle axle, the tube being rotatable relative to either or both of the rotor body and the stator, the tube being further configured to be translatably coupled to the stator such that when the hubcap is removed from the vehicle hub, the tube can be translated out of and disengaged from the stator, wherein the rotor assembly is configured to be removably mounted inside the hubcap. 13. A vehicle tire inflation system, the vehicle tire inflation system comprising: A fluid source, said fluid source being in fluid communication with a stator seal; and The rotary joint according to claim 12. 14. The vehicle tire inflation system of claim 13, wherein the hubcap has a fluid passage disposed therein, and the vehicle tire inflation system further comprises: A fluid conduit that provides sealed fluid communication between the vehicle tire and the hubcap.