Oil film bearings applied to heavy duty rolling mill drive couplings.

The present work describes an investigation related to rolling mill drive-lines in the Steel Industry with special reference to Hookes joint couplings. This coupling transmits the torque and the rotational motion, required for the rolling process, and contains four hearings which are under oscillating motion. Together with the impact loads often found in rolling mills this provides a severe operating environment which has been simulated to permit an experimental investigation of the suitability of oil film bearings for such applications. In the rig, displacements of the shaft centre, i.e. locus path or eccentricity, have been recorded versus load levels and frequencies of oscillation or rotational speeds for constant oil inlet pressure. Three different types of oil lubricant bearings have been tested under the adverse conditions of dynamic load and oscillating motion, but less severe tests for conditions of continuous motion and static load were also carried out to give reference of the behaviour of such bearings. Comparisons have been obtained between hydrodynamic bearings with axial and circumferential grooving and slot entry hybrid bearings, showing the latter to be suited to the particular application considered. Results have been compared with existing design procedures suitably modified to take account of the adverse operating conditions.