Session: 23-04, Hydrodynamic Bearings

Paper Number: 126536

126536 - Design Considerations for Directed-Lubrication Thrust Bearings Across a Wide Range of Operating Conditions With a Focus on Pressure Drop in the Oil Supply Path 

Directed-lubrication thrust bearings significantly improve a machine’s performance by reducing oil consumption requirements and, therefore, power losses. These bearings do not rely on the pumping action of the rotating collar to achieve adequate oil flow with minimal oil supply pressure like traditional flooded thrust bearings. Instead, the oil supply pressure is critical to keeping the bearing properly lubricated.  The bearing designer must carefully understand the pressure losses through the directed-lubrication bearing system to ensure that the flow of oil is maintained at the volume required for each application.  This is achieved by custom modifications within the oil flow path to suit specific goals, typically by the sizing of a single orifice.

Today, OEMs strive to produce machines that cover a wide range of operating conditions yet still maintain a “one size fits all” approach when it comes to machine components.  The thrust bearing can no longer be optimized for an ideal operating condition.  Instead, it needs to perform for a range of conditions.  This new environment accentuates the need for high levels of accuracy in both oil flow calculations and the resulting bearing performance. We discuss in this paper various methods of calculating pressure losses within a directed-lubrication thrust bearing. We highlight the unique challenges encountered in providing adequate oil flow for the wide range of operating conditions. We compare traditional calculations using classical pressure drop versus pipe length theory against calculations obtained using computational fluid dynamics, and we calibrate both methods with tests performed in-house.  Finally, we discuss the limits of our models, including scalability, dynamic effects, and tolerance effects. 

Presenting Author: Louis Krajewski Kingsbury, Inc.

Presenting Author Biography: Lou Krajewski is the Chief Engineer of Fluid Film Products at Kingsbury, Inc. in Philadelphia, Pennsylvania. His primary responsibilities include design, analysis and technical support for Kingsbury hydrodynamic bearings worldwide. He has been with Kingsbury since 2010. Since then, Mr. Krajewski has led the engineering effort for innumerable critical bearing applications in key industries such as power generation, oil and gas, and marine propulsion. He holds a B.S. degree in Mechanical Engineering Technology from Temple University and a M.S. degree in Materials Science and Engineering from North Carolina State University.

Authors:

Bruce Fabijonas Kingsbury, Inc.
Louis Krajewski Kingsbury, Inc.
Amruthkiran Hegde Kingsbury, Inc.
Richard Rodzwic Kingsbury, Inc.