Hydrodynamic bearings modeling with alternate motion

This paper presents an analysis of the lubrication problem in hydrodynamic bearings with alternate rotational motion. In contrast to conventional bearings, the shaft does not perform a complete revolution but inverts the direction of its rotation instead. The analysis follows the basic assumption of the Reynolds lubrication theory i.e. fluid inertia is neglected in the gap formed by the eccentric shaft with respect to the bearing. The differential equations of mass and momentum in the oil gap are integrated to give the velocity field, pressure distribution and hydrodynamic forces under simplified assumptions. To evaluate the model under known operational conditions a rotor dynamics approach is used. This allows evaluation of the lubrication conditions for this type of bearing.