Study of the failure criterion for non-lubricated hybrid bearings under high-speed and heavy-load conditions
The thermal softening strength failure mechanism and criterion for high-speed, heavy-load, and unlubricated hybrid bearings are proposed. This establishes an innovative theoretical foundation for their life analysis and can be applied to the design and failure analysis of auxiliary bearings in magnetic bearings.
Liu Xingnan | INET News
October 10, 2025
A research team including Ph.D. student Wang Mingqi, Research Prof. Shi Zhengang and Research Associate Prof. Liu Xingnan from the Magnetic Bearing Technology Division of the Institute of Nuclear and New Energy Technology, Tsinghua University, has revealed the fundamental failure mechanism of ceramic ball hybrid bearings under high-speed, heavy-load, and oil-free lubrication conditions- thermal softening strength failure during thermo-mechanical coupling processes, and has subsequently constructed a corresponding failure criterion, based on observations of partial spalling and thermal erosion phenomena in bearing raceways during life testing and analysis of life data. This theory emphasizes that the cooperative effect between temperature and stress fields is the dominant mechanism of bearing failure, transcending the limitations of traditional fatigue failure understanding and offering a novel perspective for life prediction under the special operating conditions. The proposed criterion represents a reasonable engineering simplification of complex physical processes, ensuring theoretical validity while accommodating practical engineering applicability, with significant practical value. The failure mechanism and criterion provide crucial theoretical foundations and methodologies for failure analysis of magnetic bearing auxiliary bearings in high-temperature gas-cooled reactors and other applications. This research will be published in Tribology International in February 2026, titled “Study of the failure criterion for non-lubricated hybrid bearings under high-speed and heavy-load conditions”. The journal is a top-tier journal in tribology, classified in the top tier (Zone 1) by the Chinese Academy of Sciences, with an impact factor of 6.9.
Link to the full paper: https://www.sciencedirect.com/science/article/pii/S0301679X25006693
