Numerical analysis on mixed lubrication performance of journal-thrust coupled microgroove bearings with different bottom shapes

The purpose of the present study is to establish a mixed lubrication model for the journal-thrust coupled microgroove bearings (also referred as coupled bearings) used for the ship shaftless rim-driven thrusters. During the hydrodynamic modelling, the coupling hydrodynamic pressure between the journal bearing and the thrust bearing is considered. The mixed lubrication performances of the microgroove journal-thrust bearing with five different bottom shapes, including rectangle, semi-ellipse, right triangle, isosceles triangle and left triangle, are compared. Based on the numerical results, the optimal microgroove bottom shape of the journal bearing and tilting angle of the thrust pad are determined. Additionally, the comparative analysis shows that the coupled bearing with left triangle microgroove bottom shape exhibits the optimal mixed lubrication performance. The numerical result also indicates that the optimal inclination angle of the thrust bearing pad is 0.01 degrees for the current simulation case.

Automated summary

The present study aims to establish a mixed lubrication model for coupled bearings used in ship shaftless rim-driven thrusters. Based on numerical results, the optimal bottom shape and tilting angle of the bearing have been determined, with the coupled bearing having a left triangle microgroove bottom shape exhibiting the best lubrication performance.