Measured and Predicted Operating Characteristics of a Tilting-Pad Journal Bearing with Jacking-Oil Device at Hydrostatic, Hybrid, and Hydrodynamic Operation

• Published in: Lubricants Vol. 6; no. 3; p. 81
• Main Authors: Hagemann, Thomas, Pfeiffer, Peter, Schwarze, Hubert
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-09-2018
• Subjects: Bearing strength; bearing test rig; Boundary conditions; Correlation analysis; Deactivation; hybrid lubrication; hydrodynamic lubrication; hydrostatic lubrication; Hydrostatic pressure; Jacking; jacking-oil; journal bearing; Journal bearings; Lift; lift-off; Liftoff; Load; Load carrying capacity; Lubricants & lubrication; Lubrication; Parameters; Predictions; Pressure distribution; Stress concentration; Thrust bearings; tilting-pad; Tolerances; Tribology; United States > US; Germany
• ISSN: 2075-4442; 2075-4442
• DOI: 10.3390/lubricants6030081

Jacking-oil pockets are applied in many journals and thrust bearing applications in order to provide a hydrostatic oil film force that ensures a wear free run-up following a successful lift-off procedure. However, all components of the jacking-oil system have to be carefully designed in order to limit costs and prevent significant disturbance of hydrodynamic operation after deactivation of lift-oil. Experimental data and predictions for a four-pad tilting-pad journal bearing in load between pivot configuration are presented. Dynamic processes of the lift-off procedure as well as characteristic parameters of stationary conditions are studied. Moreover, hydrodynamic operation and hybrid lubrication providing a combined hydrodynamic and hydrostatic pressure distribution are investigated for sliding speeds up to 20 m/s. Analyzes of lift-off procedure prove that characteristic parameters such as lift-off pressures and vertical lift displacements are considerably influenced by manufacturing tolerances and misalignments. The comparison of hydrodynamic and hybrid lubrication provides a significant increase of load carrying capacity by additional jacking-oil supply at the maximum journal speed. In summary, results of measurements and predictions correlate well for all three investigated lubrication conditions.