https://web.iitd.ac.in/~hirani/manish_verma.pdf

Tribological study of elastomeric bearings for marine propeller shaft system

The effects of geometric change due to wear on the dynamic characteristics of journal bearings are determined theoretically in both laminar and turbulent regimes. The dynamic characteristics such as spring and damping coefficients and whirl onset speed of a rigid rotor supported by two identical symmetrically aligned bearings are analyzed by a semianalytical finite element method, and the numerical results for various wear depth parameters are indicated in graphical form. The geometric change due to wear has significant effects on the principal spring coefficients and on the cross-coupled damping coefficients. The whirl onset speed for a worn journal bearing whose wear depth parameter is larger than 0.3 becomes higher than the speed for a nonworn bearing.

Performance Characteristics of Worn Journal Bearings in Both Laminar and Turbulent Regimes. Part I: Steady-State Characteristics

Stability of a rigid rotor in turbulent hydrodynamic worn journal bearings

Wear simulation for the journal bearings operating under aligned shaft and steady load during start-up and coast-down conditions

The onset and development of wear in plain hydrodynamic journal bearings under repeated cycles of starting and stopping has been studied experimentally. The wear which occurred caused easily discernable but localized changes in diametral clearance, surface finish, and roundness of the bearing's bore and these changes were measured after various numbers of operating cycles had been completed. Study of the location, within the bearings of the wear which arose, showed that it was caused entirely by the sliding which occurred during starting and that no significant contribution to the wearing process was made during stopping. It was also observed that, once an initial rapid phase of wearing was completed, the surface finish of the hardened steel shaft was reproduced in the regions of the bearing's surface which continued to be worn.

Wear Characteristics of Plain Hydrodynamic Journal Bearings During Repeated Starting and Stopping

The work described is concerned with the behavior of plain, hydrodynamic journal bearings during starting and stopping under a steady load. The starting behavior indicated that a rapid buildup of hydrodynamic forces occurred in all cases. A hydrodynamic film was formed in a very short time, after which the shaft moved in a spiral shaped whirling locus to the steady state operating position. Prior to separation of the shaft and bearing surfaces, the contact was mainly a sliding situation with little or no initial rolling. At stopping, the shaft followed a typical hydrodynamic locus until rotation ceased and then a squeeze film trajectory to the final resting position.

P. B. Davies

Papers

Wear Characteristics of Plain Hydrodynamic Journal Bearings During Repeated Starting and Stopping

The Behavior of Plain Hydrodynamic Journal Bearings During Starting and Stopping