To mitigate seal failure caused by excessive thermal deformation leading to the failure of magnetic mechanical seals, this paper proposes a novel magnetic seal structure, a single-stage stepped structure in the rotating ring. A coupled multi-physical field model incorporating magnetic-fluid-solid-thermal interactions was established, and its accuracy is verified through testing. The study then analyses and optimizes the heat balance characteristics of the magnetic mechanical seal. Results indicate that the novel stepped structure enhances convective heat transfer through the local pressure drop effect, improving the temperature distribution and reducing thermal deformation at the seal end face. Compared with typical structure, the structure maintains the maximum temperature of the end face within 34.7 °C under the working condition of medium pressure 0.49 MPa; at a rotational speed of 6500 r/min, the maximum temperature of the end face decreases by 11.56 %, and the relative deformation is reduced by 18.3 %. Furthermore, the structure increases the limit speed of seal Thermal balance from 6000 r/min to 7500 r/min, and raises the limit medium pressure from 0.31 MPa to 0.42 MPa, significantly enhancing the magnetic mechanical seal's adaptability to extreme working conditions, and effectively broadens the magnetic mechanical seal Thermal balance working conditions.
Liu et al. (Fri,) studied this question.