Patent ID: 8070177

Claim:
In a steer axle assembly for a trailer having a laterally extending beam with a beam axis having respective kingpin sleeve at opposite ends thereof, for supporting respective left and right kingpins each said kingpin having a respective kingpin axis generally orthogonal to said beam axis, said kingpin axes being generally parallel to each other; said kingpin sleeves having generally parallel upper and lower kingpin sleeve thrust faces which are generally parallel to each other and to said beam axis; respective left and right yokes each having an upper yoke sleeve extending about a respective of said kingpins above said upper kingpin sleeve thrust faces and a lower yoke sleeve extending about a respective of said kingpins below said lower kingpin sleeve thrust faces, said yokes being swivelable about said kingpins about said kingpin axes; each said upper yoke sleeve having an upper yoke sleeve thrust face generally parallel to and slideably engaging said upper kingpin sleeve thrust face; each said lower yoke sleeve having a lower yoke sleeve thrust face facing said lower kingpin sleeve thrust face generally parallel thereto but spaced apart therefrom; each said yoke supporting a respective axle spindle having a spindle axle assembly with a spindle axis generally parallel to said beam axis; a tie rod assembly extending between said left and right yokes for restraining said yokes to swivel in unison; a stabilizer assembly acting between said tie rod assembly and said beam to stabilize said swivelling of said yokes about said kingpins; the improvement comprising: a respective tapered roller thrust bearing extending between each said lower kingpin yoke thrust face and each said lower kingpin sleeve thrust face for transferring load between said lower yoke sleeve and said kingpin sleeve while allowing said yokes to swivel about said kingpins; upper and lower needle bearing assemblies extending respectively between said upper and lower yoke sleeves and said kingpins to guide said swivelable movement of said yokes about said kingpins; upper and lower kingpin caps securable across said upper and lower yoke sleeves respectively above and below said kingpins to seal opposite ends of said kingpins within said yoke sleeves; each said kingpin cap having a grease passage extending therethrough for admitting grease into an interior of said yoke sleeves and a grease fitting releaseably coupleable to a pressurized grease supply and sealingly engaging said grease passage to introduce grease into said grease passage; upper and lower kingpin seals respectively adjacent said upper and lower yoke thrust faces and extending about kingpins to sealingly engage said kingpins for inhibiting the ingress of dirt and moisture into said yoke sleeves yet allowing excess grease to escape.