TY - JOUR
T1 - Predicting centrifugally-driven lubricant outflow from porous bearing cages
AU - Feng, Xiangyu
AU - Zhu, Pengzhe
AU - Wang, Wenzhong
N1 - Publisher Copyright:
© 2026 Elsevier Ltd
PY - 2026/2/1
Y1 - 2026/2/1
N2 - Aerospace bearings in spacecraft mechanisms require decades of autonomous operation under extreme conditions, making precise control of lubricant release from porous bearing cages essential. However, predicting this release behavior remains a significant challenge. This study develops a two-scale predictive framework derived from Navier-Stokes equations for centrifugally-driven lubricant outflow, encompassing both pore-scale and macroscale criteria. A characteristic parameter for quantifying the lubricant outflow state within porous cages was developed, which is governed by seven controlling parameters: pore size, rotation speed, rotation radius, lubricant density, surface tension, characteristic contact angle, and characteristic channel length. Validation through finite element simulations, centrifugal experiments, and literature data demonstrates strong agreement between predictions and observations. The resulting phase diagrams provide systematic design guidance for aerospace bearing cages, enabling the determination of outflow speeds and optimization of pore structures for specific operational requirements. This physics-based approach establishes the theoretical foundation and practical tools essential for next-generation aerospace bearing systems.
AB - Aerospace bearings in spacecraft mechanisms require decades of autonomous operation under extreme conditions, making precise control of lubricant release from porous bearing cages essential. However, predicting this release behavior remains a significant challenge. This study develops a two-scale predictive framework derived from Navier-Stokes equations for centrifugally-driven lubricant outflow, encompassing both pore-scale and macroscale criteria. A characteristic parameter for quantifying the lubricant outflow state within porous cages was developed, which is governed by seven controlling parameters: pore size, rotation speed, rotation radius, lubricant density, surface tension, characteristic contact angle, and characteristic channel length. Validation through finite element simulations, centrifugal experiments, and literature data demonstrates strong agreement between predictions and observations. The resulting phase diagrams provide systematic design guidance for aerospace bearing cages, enabling the determination of outflow speeds and optimization of pore structures for specific operational requirements. This physics-based approach establishes the theoretical foundation and practical tools essential for next-generation aerospace bearing systems.
KW - Bearing cages
KW - Centrifugal effect
KW - Lubricant outflow state
KW - Lubrication systems
KW - Porous materials
KW - Tribology
UR - https://www.scopus.com/pages/publications/105026659443
U2 - 10.1016/j.ijmecsci.2026.111184
DO - 10.1016/j.ijmecsci.2026.111184
M3 - Article
AN - SCOPUS:105026659443
SN - 0020-7403
VL - 311
JO - International Journal of Mechanical Sciences
JF - International Journal of Mechanical Sciences
M1 - 111184
ER -