Mother-and-child sleeve maintenance-free thrust joint bearing

The invention provides a mother-and-child sleeve maintenance-free thrust joint bearing. The mother-and-child sleeve maintenance-free thrust joint bearing is characterized in that a lower thrust jointbearing seat ring is provided with a coaxial second-stage hole; a lower thrust joint bearing shaft ring is provided with a coaxial second-stage hole; an upper thrust joint bearing seat ring is embedded in a large-diameter hole of the lower thrust joint bearing shaft ring; the diameter of the coaxial through hole formed in the upper thrust joint bearing seat ring is larger than that of the upper thrust joint bearing shaft ring; a stepped shoulder formed by a first shaft section and a second shaft section of a connecting bolt abuts against the second-stage hole formed in the lower thrust joint bearing seat ring; a stepped shoulder formed by a third shaft section and a fourth shaft section abuts against the upper thrust joint bearing shaft ring; and a nut is fastened and screwed on the part,exposed out of an upper th