Sealing structure for bearing cavity of turbine rotor of core engine

The invention belongs to the technical field of technical gas turbines, and particularly relates to a sealing structure for a bearing cavity of a turbine rotor of a core engine, which is used for replacing a low-pressure turbine rotor to be connected with the core engine and comprises a sealing shaft barrel and an oil cavity sealing bushing, the sealing shaft barrel comprises a rear shaft section, a mounting disc part and a front shaft section; the rear shaft section, the mounting disc part and the front shaft section are arranged in the direction of the core machine from back to front; the front shaft section can extend into the long labyrinth ring, so that labyrinth seal is formed by the long labyrinth ring and the high-pressure turbine shaft; the front abutting face of the mounting disc part can abut against the end face of the rear side of the bearing oil injection ring, so that the third oil cavity is closed. And a second oil cavity is formed among the oil cavity sealing bushing, the turbine fulcrum fram