Influence of Structure Deformation on Leakage Characteristics in Labyrinth Seal inside the Cryogenic Internal-cooling Spindle

Labyrinth seal is the key structure to ensure the sealing performance between stator and rotor in rotating machinery. When used to seal the cryogenic fluid in the spindle of cryogenic machine tool, the labyrinth seal bears a very large temperature load and stress load, which will produce structural deformation and indirectly affect the sealing performance. In order to research the influence of structural deformation on the performance of labyrinth seal in the spindle of cryogenic machine tool, the temperature field, the deformation law of labyrinth seal, leakage characteristics of labyrinth seal in cryogenic fluid are studied based on the numerical analysis method of multi physical field coupling and some mechanics.Through the analysis, the temperature field distribution of the seal structure, the sealing clearance after deformation are obtained, and the leakage model considering the structure deformation is established. The leakage at low temperature of -188.56 ℃ increased by two times, the result shows that the thermal shrinkage deformation of labyrinth seals results in the deterioration of seal performance under the influence of temperature load. By comparing and analyzing the leakage of several working conditions, the relative errors are less than 6%, the validity of the proposed leakage model considering structural deformation is verified.