An Evaluation of Starting-Load Capacity and Static Friction in Babbitt-Lined,Hydrodynamic Journal Bearings

A recent application called for starting 127-mm (5-in) diameter, babbitt-lined hydrodynamic journal bearings under unit loads of about 10.34 MPa (1500 psi). In this application, the load was imposed only a few seconds before rotation could be started and hydrostatic jacking was not permitted. This paper presents the results of a test effort in which one full-size bearing was subjected to several hundred starts under unit loads ranging from 3.4 to 15.5 MPa (500 to 2250 psi). The dwell time between load application and start of rotation was varied in the test from less than one second to more than one hour. The paper also provides a review of the relevant literature, as well as calculations of the contact zone temperature during starts under boundary lubrication conditions.