Study on the tribo-dynamic performances of water-lubricated microgroove bearings during start-up

Abstract

In the present works, a tribo-dynamic model considering the transient friction force is proposed to study the tribo-dynamic performances of the Water-Lubricated Microgroove Bearings (WLMB) during start-up under three acceleration modes. Based on the developed model, the tribo-dynamic performances of WLMB between three bottom shapes, i.e. triangle, left triangle, right triangle, are compared. In addition, the effects of the key factors, including the acceleration time, bearing shell thickness, surface parameters and dry friction coefficient, on the tribo-dynamic performances of WLMB are identified. Numerical results demonstrate that at the initial stage of start-up, the transient horizontal friction force drives the rotor along the opposite direction of rotation. The comparative analysis indicates that the sinusoidal acceleration mode and left triangle bottom shape may be recommended to yield the optimal tribo-dynamic performances of WLMB during start-up. The parametric studies reveal that during start-up, the acceleration time and the surface roughness significantly affect the tribo-dynamic performances, whereas the asperity curvature slightly affects the tribo-dynamic performances. Furthermore, the numerical results demonstrate that the dry friction coefficient plays an important role in tribo-dynamic analysis for WLMB during start-up.