Central tire inflation system for steering drive axle

A vehicle steering live spindle wheel end assembly (1) including a tire inflation system providing pressurized air to a pneumatic tire directly through said wheel end assembly (1), said wheel end assembly (1) comprising:

• a steering knuckle (10) having an inlet passageway (11) formed directly therethrough, said inlet passageway (11) connected to a source of pressurized air;
• a spindle assembly (4) rotatably mounted to said steering knuckle (10) and including a wheel hub member (5) and a coupling ring member (16) non-rotatably coupled to said wheel hub member, said coupling ring member (16) having a plurality of outlet passageways (24) formed therethrough, said outlet passageways (24) being in fluid communication with a pneumatic tire at outward ends of said outlet passageways (24);
• a drive shaft (12) rotatably mounted within said steering knuckle (10) and drivingly coupled to said spindle assembly (4), said drive shaft (12) includes a substantially cylindrical flange portion (12a) and a splined end (12b) non-rotatably coupled to said coupling ring member (16) of said spindle assembly (4);
• a slip-ring seal assembly (30) including a seal carrier (32) non-rotatably mounted to said steering knuckle (10), a first seal member (40) and a second seal member (42) both extending from said seal carrier (32) in axially spaced relationship so as to define a rolling seal chamber (44) between said first seal member (40) and said second seal member (42);
• said first seal member (40) being in sliding sealing contact with said coupling ring member (16) of said spindle assembly (4) and said second seal member (42) being in sliding sealing contact with said cylindrical flange portion (12a) of said drive shaft (12);
• said seal carrier (32) including a communication hole (34) aligned with said inlet passageway (11) in said steering knuckle (10) to provide a fluid communication between said inlet passageway (11) and said rolling seal chamber (44) and a drain passage (36) provided to remove any contamination from said seal chamber (44), a first end of said drain passage (36) is open to said seal chamber (44) and a second end of said drain passage (36) is open to an area external to said seal chamber (44) and is adapted to be closed by a removable threaded plug (38);
• and
• said outlet passageways (24) being in fluid communication with said rolling seal chamber (44) thereby establishing a fluid communication path between said source of pressurized air and said pneumatic tire.

A vehicle steering live spindle wheel end assembly (101) including a tire inflation system providing pressurized air to a pneumatic tire directly through said wheel end assembly (101), said wheel end assembly (101) comprising:

• a steering knuckle (10) having an inlet passageway (11) formed directly therethrough, said inlet passageway (11) connected to a source of pressurized air;
• a wheel hub member (105) rotatably mounted to said steering knuckle (10), said wheel hub member (105) having a plurality of outlet passageways (124) formed therethrough, said outlet passageways (124) being in fluid communication with a pneumatic tire at outward ends of said outlet passageways (124);
• a drive shaft (12) rotatably mounted within said steering knuckle (10) and drivingly coupled to said wheel hub member (105), said drive shaft (12) includes a substantially cylindrical flange portion (12a) and a splined end (12b) non-rotatably coupled to said wheel hub member (105);
• a slip-ring seal assembly (30) including a seal carrier (32) non-rotatably mounted to said steering knuckle (10), a first seal member (40) and a second seal member (42) both extending from said seal carrier (32) in axially spaced relationship so as to define a rolling seal chamber (44) between said first seal member (40) and said second seal member (42);
• said first seal member (40) being in sliding sealing contact with said wheel hub member (105) and said second seal member (42) being in sliding sealing contact with said cylindrical flange portion (12a) of said drive shaft (12);
• said seal carrier (32) including a communication hole (34) aligned with said inlet passageway (11) in said steering knuckle (10) to provide a fluid communication between said inlet passageway (11) and said rolling seal chamber (44) and a drain passage (36) provided to remove any contamination from said seal chamber (44), a first end of said drain passage (36) is open to said seal chamber (44) and a second end of said drain passage (36) is open to an area external to said seal chamber (44) and is adapted to be closed by a removable threaded plug (38);
• and
• said outlet passageways (124) being in fluid communication with said rolling seal chamber (44) thereby establishing a fluid communication path between said source of pressurized air and said pneumatic tire.