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: An assembly to be mounted in an axle spindle for communicating pressurized air to a rotary union in a tire inflation system. The assembly includes an arbor having an air flow channel extending therethrough, a flange intermediary of the arbor ends and an axially inclined portion proximate the flange. A sealing member is carried by the flange for forming a seal with the axle spindle. A split ring locking assembly is disposed about the inclined portion of the arbor that is comprised of a plurality of segments held by an expansible retention spring. The segments move radially outwardly upon the locking assembly being moved along the inclined arbor portion and engage the axle spindle, securing the plug assembly within the spindle. A fastening member threadably engages the arbor for urging the locking assembly along the inclined arbor portion to effect securement of the plug assembly within the axle spindle.

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 assembly to be mounted in an axle spindle for communicating pressurized air from the axle to a rotary union in a tire inflation system. The assembly includes an arbor having an air flow channel extending therethrough, a flange intermediary of the arbor ends and an axially inclined portion proximate the flange. A sealing member is carried by the flange for forming an airtight seal with the axle spindle. A split ring locking assembly is disposed about the inclined portion of the arbor that is comprised of a plurality of segments held by an expansible retention spring. The segments move radially outwardly upon the locking assembly being moved along the inclined arbor portion and engage the axle spindle, securing the plug assembly within the spindle, A fastening member threadably engages the arbor for urging the locking assembly along the inclined arbor portion to effect securement of the plug assembly within the axle spindle.