Predicting Oil Ring Self-Lubricated Sleeve Bearing Temperature Rise and its Effect on Shaft Criticals

Several steps are involved in predicting the temperature rise within the babbitt/oil film of sleeve bearings. Initially, the viscous friction loss developed in the oil film is determined. This loss depends on the speed, length, and diameter of the journal, oil viscosity, and diametral clearance. A heat balance study then compares heat loss generation and dissipation rates. The final consideration is the ability of the oil rings to deliver the necessary oil flow rate. An approach for predicting sleeve bearing temperature rise and the adequacy of oil ring lubrication is described. It is shown that some of the design variables affecting the bearing temperature rise also influence the bearing oil film stiffness. The value of this stiffness plays a vital role in determining the shaft critical speed.