Abstract: A rotary union assembly for use with a tire inflation system includes a hollow tube configured to deliver air between proximal and distal ends, a bullet having a central axial aperture receiving the tube therethrough, a proximal retaining structure defined on the proximal end of the tube, and a distal retaining structure defined on a distal end of the tube, configured to retain the bullet on the tube therebetween. A cartridge is coupled to a distal end of the tube and includes one or more apertures on a sidewall thereof in fluid communication with the tube. In use, the rotary union assembly is coupled between a non-rotating axle of a vehicle and the rotating hubcap of a tire rotating about the axle and may be removed as a unit for repair and/or replacement of wear parts on the assembly.

Abstract: The air transmission structure includes a stator—having an annular outer wall with at least one aperture, an air inlet, and an air passage between the air inlet and the at least one aperture on the annular outer wall—biased against the non-rotating spindle. A housing includes interior annular walls mounted in radially spaced relation with the annular outer wall of the stator to form an annular cavity therebetween, and at least one aperture formed through the interior annular wall, and air outlet, and an air passage between the at least one aperture and air outlet. A seal is inserted within the annular cavity and defines a radial air passage between the apertures defined within the stator annular outer wall and the housing interior annular wall. An annular bearing between the stator and housing is configured to allow the housing to rotate with respect to the stator.

Abstract: A rotary union assembly for use with a tire inflation system includes a hollow tube configured to deliver air between proximal and distal ends, a bullet having a central axial aperture receiving the tube therethrough, a proximal retaining structure defined on the proximal end of the tube, and a distal retaining structure defined on a distal end of the tube, configured to retain the bullet on the tube therebetween. A cartridge is coupled to a distal end of the tube and includes one or more apertures on a sidewall thereof in fluid communication with the tube. In use, the rotary union assembly is coupled between a non-rotating axle of a vehicle and the rotating hubcap of a tire rotating about the axle and may be removed as a unit for repair and/or replacement of wear parts on the assembly.

Abstract: The air transmission structure includes a stator—having an annular outer wall with at least one aperture, an air inlet, and an air passage between the air inlet and the at least one aperture on the annular outer wall—biased against the non-rotating spindle. A housing includes interior annular walls mounted in radially spaced relation with the annular outer wall of the stator to form an annular cavity therebetween, and at least one aperture formed through the interior annular wall, and air outlet, and an air passage between the at least one aperture and air outlet. A seal is inserted within the annular cavity and defines a radial air passage between the apertures defined within the stator annular outer wall and the housing interior annular wall. An annular bearing between the stator and housing is configured to allow the housing to rotate with respect to the stator.

Abstract: A failure tolerant tire inflation system for supplying pressurized air from an onboard source to the vehicle tires in the event of a pressure drop in one or more of the tires below a predetermined level. The system includes a tire inflation valve communicable with the source of pressurized air, a tire selector valve assembly for selectively communicating air from the tire inflation valve with the vehicle tires, a plurality of valve assemblies each communicating with at least one tire and selectively communicating with the tire selector valve assembly. A controller selectively activates and deactivates the tire inflation valve and valve assemblies to sequentially check the pressure in the tires and direct air to any underinflated tire. A transducer is provided for detecting the tire pressure levels upon the opening of the valve assembly communicating with that tire and communicating the underinflated condition to the controller.

Abstract: A failure tolerant tire inflation system for supplying pressurized air from an onboard source to the vehicle tires in the event of a pressure drop in one or more of the tires below a predetermined level. The system includes a tire inflation valve communicable with the source of pressurized air, a tire selector valve assembly for selectively communicating air from the tire inflation valve with the vehicle tires, a plurality of valve assemblies each communicating with at least one tire and selectively communicating with the tire selector valve assembly. A controller selectively activates and deactivates the tire inflation valve and valve assemblies to sequentially check the pressure in the tires and direct air to any underinflated tire. A transducer is provided for detecting the tire pressure levels upon the opening of the valve assembly communicating with that tire and communicating the underinflated condition to the controller.

Abstract: Preferably, an embodiment of a tire inflation system includes at least an axle housing a pressurized fluid, a hubcap supported by the axle and having an interior and an exterior, and a rotary union axially aligned with the axle and mounted to the hubcap from the exterior of the hubcap. The rotary union preferably includes at least a rotating portion and a non-rotating portion, the rotating portion rotates with hub cap, and the non-rotating portion including at least a fluid conduit defining an air passage there through. The air conduit is preferably in fluid communication with the source of pressurized air, and is preferably configured for conducting pressurized air from said source of pressurized air to a tire mounted to the wheel of the vehicle, and for developing a dynamic seal between the fluid conduit and the rotating portion.

Abstract: Preferably, a tire inflation system includes a hub cap secured to a wheel attached to an axle of a vehicle, which provides a source of pressurized air. The tire inflation system preferably includes a rotary union assembly with a rotating portion and a non-rotating portion, the rotating portion attachable to the exterior of the hub cap for rotation with the hub cap. The non-rotating portion preferably includes a stationary shaft in fluid communication with the source of pressurized air, the stationary shaft defining an air passage therethrough which participates in conducting pressurized air to the tire. An end of the stationary shaft preferably provides a first bearing surface and a housing is rotatably mounted thereon for rotation with the hub cap. The rotating portion preferably includes a rotary member rotating with the housing, the rotary member defining a second bearing surface disposed in abutment with the first bearing surface.

Abstract: Preferably, an embodiment of a tire inflation system includes at least an axle housing a pressurized fluid, a hubcap supported by the axle and having an interior and an exterior, a rotary union axially aligned with the axle and mounted to the hubcap from the exterior of the hubcap, and a lubrication trap axially aligned with the axle, supporting the rotary union and secured to the hubcap from the exterior of the hubcap for rotation with the hubcap. In another embodiment, a tire inflation system includes at least an axle housing a pressurized fluid, a hubcap supported by the axle and having an interior and an exterior, a rotary union axially aligned with the axle and mounted to the hubcap from the exterior of the hubcap, and a bushing axially aligned with the axle and disposed between the rotary union and the hubcap.

Abstract: Preferably, an embodiment of a tire inflation system includes at least an axle housing a pressurized fluid, a hubcap supported by the axle and having an interior and an exterior, a rotary union axially aligned with the axle and mounted to the hubcap from the exterior of the hubcap, and a lubrication trap axially aligned with the axle, supporting the rotary union and secured to the hubcap from the exterior of the hubcap for rotation with the hubcap. In another embodiment, a tire inflation system includes at least an axle housing a pressurized fluid, a hubcap supported by the axle and having an interior and an exterior, a rotary union axially aligned with the axle and mounted to the hubcap from the exterior of the hubcap, and a bushing axially aligned with the axle and disposed between the rotary union and the hubcap.

Abstract: Preferably, a tire inflation system includes a hub cap secured to a wheel attached to an axle of a vehicle, the axle providing a source of pressurized air. The tire inflation system preferably includes a rotary union assembly with a rotating portion and a non-rotating portion, the rotating portion attachable to the exterior of the hub cap for rotation with the hub cap. The non-rotating portion preferably includes a non-rotating shaft defining an air passage therethrough in fluid communication with the source of pressurized air for transferring pressurized air from the source to the tire. An end of the non-rotating shaft preferably provides a first bearing surface and a housing is rotatably mounted thereon for rotation with the hub cap. The rotating portion preferably includes a rotary member rotating with the housing, the rotary member defining a second bearing surface disposed in abutment with the first bearing surface.

Abstract: A rotary union assembly for an automatic tire inflation system for maintaining the pressure in the tires on a tractor trailer or other vehicle having a source of pressurized air for communication with the tires. The assembly communicates the tires with the air source through the axle interior using a conduit having a rigid portion and a flexible portion that extends between a support in the axle spindle and a rotary union housing secured against the outside end surface of the hub cap so as to be outside the wheel lubrication compartment and rotatable with the hub cap. The two-component conduit allows for a durable seal with the support in the axle spindle and accommodates misalignment of the rotary union housing with the conduit support. Relief valves in the housing prevent excessive pressure buildups in the housing and in the hub cap in the event of an air leak.

Abstract: Preferably, a rotary union assanblv includes at least a stationary tubular member defining an upstream end portion extending axially into an interior of an axle of a vehicle containing a source of pressurized air, and a downstream end portion upon which a housing is rotatably mounted. The housing of the preferred rotary union assembly is attachable to the exterior of a hub cap of the vehicle for rotation with the hub cap, and the housing preferably defines at least one air passagway extending therethrough that the tubular member communicates the source of the pressurized air with the passageway in the housing, and promotes passage of the pressurized air from the source of the pressurized air to a tire of the vehicle. Further, a rotary element is disposed within the housing of the preferred embodiment and provides a rotary element in abutting disposition with a stationary element.

Abstract: A rotary union assembly for use in an automatic tire inflation system for maintaining the desired pressure in the tires on a tractor trailer or other vehicle having pressurized axles. The assembly communicates the valve stems on a pair of adjacent tires with the axle interior through the use of a flexible tube extending between a stationary first fitting threadably engaged in the axle spindle and a rotary housing secured against the outside end surface of the hub cap so as to be positioned exteriorly of the wheel lubrication compartment and rotatable with the hub cap. The first fitting defines an open channel extending axially therethrough and includes an o-ring seal extending about the channel and forming an airtight seal within the fitting about the tube.

Abstract: A rotary union assembly for use in an automatic tire inflation system for maintaining the desired pressure in the tires on a tractor trailer or other vehicle having pressurized axles. The assembly communicates the valve stems on a pair of adjacent tires with the axle interior through the use of a flexible tube extending between a stationary first fitting threadably engaged in the axle spindle and a rotary housing secured against the outside end surface of the hub cap so as to be positioned exteriorly of the wheel lubrication compartment and rotatable with the hub cap. The first fitting defines an open channel extending axially therethrough and includes an o-ring seal extending about the channel and forming an airtight seal within the fitting about the tube.

Abstract: An expansion plug filter assembly adapted to be mounted in an axle spindle for communicating filtered air from an axle to a rotary union assembly in a tire inflation system. The assembly includes a head portion, a body portion, an internal air flow channel extending longitudinally through the head and body portions. A press plate cavity is provided in the head portion of the assembly. A filter unit is carried by the body portion and a press plate is disposed within the press plate cavity. An o-ring mounted in a groove about the head portion provides an airtight seal between the head portion and the interior of the axle spindle. Tightening a plurality of securement bolts embedded in the head portion draws the press plate into the press plate cavity and causes a downstream portion of the head portion of the assembly to expand against the spindle to releasably secure the assembly within the spindle such that air passing therethrough is first caused to flow through the filter unit.

Abstract: A rotary union assembly for use in an automatic tire inflation system for maintaining the desired pressure in the tires on a tractor trailer or other vehicle having pressurized axles. The assembly communicates the valve stems on a pair of adjacent tires with the axle interior through the use of a flexible tube extending between a stationary first fitting threadably engaged in the axle spindle and a rotary housing secured against the outside end surface of the hub cap so as to be positioned exteriorly of the wheel lubrication compartment and rotatable with the hub cap. The first fitting defines an open channel extending axially therethrough and includes an o-ring seal extending about the channel and forming an airtight seal within the fitting about the tube.

Abstract: An air control system having an air supply extending into the inside of the axles of a trailer to the tires. An air sealing barrier is connected adjacent each end of the axle for sealing air inside of the axle between the barriers. A pneumatic rotary union is positioned in each barrier and includes an air passageway in communication with the air inside of the axle and is connected to a rotatable air connection extending through a lubrication compartment at the end of the axle. An oil sight plug having a relief valve is connected to the lubrication compartment.