Investigation on Lubrication Performance of Water-Lubricated Bearings Considering Elastic Modulus and Cavitation Effect

Water-lubricated bearings are susceptible to cavitation during operation due to the low viscosity and high cavitation sensitivity of water, and the cavitation-induced lubrication performance differs significantly among bearing materials with different elastic modulus. To systematically investigate the evolution of lubrication performance of water-lubricated bearings under the coupled effect of elastic modulus and cavitation, a hydrodynamic lubrication model considering bushing deformation and surface roughness is established based on the JFO boundary condition. Three typical liner materials, namely thordon, rubber alloy, and graphite, are selected. The influences of load, radial clearance, and length-to-diameter ratio on bearing lubrication performance and the cavitation-deformation coupling sensitivity coefficient Kcm are systematically analyzed under elastohydrodynamic (EHL) and mixed lubrication (ML) conditions. The results show that under EHL, the elastic modulus plays a dominant role in cavitation evolution: a higher modulus leads to smaller elastic deformation, a larger cavitation area ratio, and higher cavitation-deformation coupling sensitivity. Under ML, the involvement of asperity contact makes the cavitation behavior more complex, and the cavitation area no longer exhibits a monotonic relationship with the elastic modulus; a non-monotonic peak is observed for the rubber alloy under certain conditions. Meanwhile, increasing the load raises the water film pressure, contact pressure, friction coefficient, and Kcm; increasing the radial clearance and length-to-diameter ratio generally reduces the cavitation area ratio and coupling sensitivity, with the length-to-diameter ratio exhibiting the most significant regulating effect. Overall, a higher elastic modulus reduces the elastic deformation of the bearing but significantly increases the friction coefficient and cavitation sensitivity, making the lubrication performance more susceptible to cavitation effects. The findings reveal the mechanism by which elastic modulus influences cavitation evolution and lubrication performance of water-lubricated bearings, providing a theoretical basis for material selection and anti-cavitation design under low-speed heavy-load and high-speed conditions.