The influence of local wear and contact roughness on mixed lubrication of marine stern bearing with misaligned shaft

The marine stern bearing provides supporting force by lubricating film to minimise the contact friction with the propeller shaft. A model considers local wear and asperity contact is proposed to investigate the mixed lubrication of bearing with misalignment. The finite difference method and over-relaxation iteration method are employed to solve the average Reynolds equation. The lubrication behaviour includes hydrodynamic pressure, film thickness, contact force and friction coefficient were calculated. The influence of sliding speed, local wear, contact roughness, misalignment angle, elastic deformation and eccentricity ratio is discussed in detail. The critical speed from mixed lubrication to fluid lubrication is obtained by employing the Stribeck curve. Moreover, the dimensionless average hydrodynamic pressure, film thickness and the peak value of contact force are compared.

Automated summary

The marine stern bearing provides support by minimizing contact friction with the propeller shaft through a lubricating film. A model considering local wear and asperity contact is used to study the mixed lubrication of misaligned bearings. The finite difference method and over-relaxation iteration method are used to solve the average Reynolds equation and calculate lubrication behavior such as hydrodynamic pressure, film thickness, contact force, and friction coefficient. The effects of sliding speed, local wear, contact roughness, misalignment angle, elastic deformation, and eccentricity ratio are discussed, and the critical speed for transitioning from mixed to fluid lubrication is determined using the Stribeck curve. Moreover, the dimensionless average hydrodynamic pressure, film thickness, and peak value of contact force are compared.