Sealing structure suitable for guide-vane-free contra-rotating turbine rotating disc cavity rim

The invention discloses a sealing structure suitable for a guide-vane-free counter-rotating turbine rotating disc cavity rim, and the sealing structure for the guide-vane-free counter-rotating turbine rotating disc cavity rim is composed of a protruding structure and a low-pressure turbine blade disc rim, wherein the protruding structure is arranged on a high-pressure turbine blade disc rim, has a certain divergence angle and faces the main flow direction. According to the structure, by optimizing the airflow dynamic state between the high-pressure turbine blade disc rims and the low-pressure turbine blade disc rims, the pressure gradient of the gaps between the high-pressure turbine blade disc rims and the low-pressure turbine blade disc rims can be reduced, boundary layer separation of the low-pressure turbine blade disc rims can be delayed, the boundary layer fluid flow speed of the high-pressure turbine blade disc rims can be increased, and rim sealing vortexes are moved upwards, so that the strength of t