A Model Configuration For Studying Stationary Grease Bleed In Rolling Bearings

Abstract

Five common ball bearing greases were studied using a grease-on-paper test configuration, where the bleeding of greases is described by the dynamics of a driving capillary pressure provided by the paper and its opposing counterpart in the grease matrix. The Washburn-like model for extracting the retaining capillary pressure, determined by the affinity of the oil for the grease matrix, has proven to be applicable for greases made of various type of thickeners and base oils, and can potentially contribute to modelling the bleeding of stationary grease as well as to monitoring the change in bleeding properties of greases in a bearing.