Long-service-life composite bearing for combustion gas turbine

The invention belongs to the technical field of combustion gas turbine equipment and particularly relates to a long-service-life composite bearing for a combustion gas turbine. The long-service-life composite bearing comprises a ball bearing and a thrust bearing. The thrust bearing comprises a thrust bearing bush and a thrust bearing disc, wherein the thrust bearing bush and the thrust bearing disc are mounted on a thrust bearing seat. The mean thickness of an oil film of the thrust bearing is adjusted through a first adjustment ring. The ball bearing is mounted on a ball bearing seat. The ball bearing is matched with a main elastic ring and a subsidiary elastic ring. The matching predeformation amount of the main elastic ring and the subsidiary elastic ring is adjusted and fixed through asecond adjustment ring and a check ring. The safety clearance between the thrust bearing disc and the ball bearing seat is set through a third adjustment ring. The ball bearing and the axial thrust bearing are fixed to the end face of a same flange. Compared with a common ball bearing, the maximum bearing capacity of the ball bearing can be set by designing the main elastic ring and the subsidiary elastic ring; and when the bearing load exceeds a set value, the remaining load can be borne by the thrust bearing, so that the service life of the ball bearing is greatly prolonged.