US Patent 7207365 Central tire inflation system rotary air union

A central tire inflation system for maintaining tire inflation on a vehicle having a torque transfer sleeve connected between an axle plug assembly and a stationary shaft on the rotary union assembly. A flexible conduit extends through the axle plug to the rotary union assembly and is used to provide air pressure to tires connected to the rotary union assembly. The torque transfer sleeve limits rotational torque on the flexible conduit. Primary and secondary seals are provided on the rotary union assembly as well. A vent chamber between the primary and secondary seals allows the release of air which exits the primary seal, which prevents pressure from entering the lubrication area of the rotary union assembly.