Numerical study on transient mixed lubrication response for multiple grooves water-lubricated bearings under non-linear shock with 3D thermal effect

Abstract

The main purpose of this study is to assess the transient mixed lubrication performance of multiple grooves water-lubricated bearings subjected to external shock considering 3D thermal behavior, and design a groove arrangement to reduce the transient contact force under external shock based on the numerical prediction. The effectiveness of the present numerical simulation is verified by the comparisons with the published results. Based on the numerical study, the transient mixed lubrication behaviors under different shock directions and amplitudes are revealed. The results demonstrate that, due to the hydrodynamic loss of the macro groove (depth is 1.5 mm), the transient mixed lubrication performance of the full groove water-lubricated bearing is poor, especially when the shock direction is horizontal. In order to improve transient tribo-dynamic behavior of the full groove water-lubricated bearing, the four-grooved and six-grooved (partial-grooved) water-lubricated bearings are designed, and its effectiveness is proved by numerical results. Subsequently, the effects of the radial clearance, bush thickness and water-lubricated material on the transient contact force of the partial-grooved water-lubricated bearing are evaluated. Numerical results indicate that the transient contact force is weakened with the increasing of radial clearance, and transient contact performance is improved with the increasing of bush thickness for the vertical shock. Additionally, the simulation results demonstrate that the water-lubricated material with lower hardness and elastic modulus has smaller transient contact force under external shock.

Influence of bearing waviness on the lubrication performances of coupled journal-thrust water-lubricated bearings

“…Then the finite difference method (FDM) is used to convert the average Reynolds equation into a formal form, and the successive over relaxation (SOR) is used for iterative solving to obtain the node fluid pressure. The convergence accuracy of the iterative process of Reynolds equation is set to be 10 −5 [30]. When the accuracy of the contact pressure and fluid pressure reaches 10 −5 , the change is not significant, it is judged that the pressure converges.…”