Investigation Of Hydrostatic Bearings For Use In High Pressure Cryogenic Turbopumps

The objectives of this program were to (1) establish operating parameters and design criteria for hydrostatic bearings used in high-pressure liquid oxygen and liquid hydrogen turbopumps, (2) determine the extent of performance increases that may be realized by the use of hydrostatic bearings, and (3) demonstrate the application of hydrostatic bearings to high-pressure turbopumps by modifying an existing turbopump design for their incorporation. An analytical design study was made of a liquid oxygen/liquid hydrogen high-pressure 250,000-lb thrust rocket engine cycle with turbopumps using hydrostatic bearings. Conceptual designs were made of the two turbopumps, and the hydrostatic bearing operating parameters were thereby established. The engine cycle and the turbopumps from this study were then compared with an engine cycle using turbopumps designed with rolling element bearings and the advantages or improvements in performance were determined. A hydrostatic bearing computer design program was developed under subcontract by Mechanical Technology, Inc. and was used to design bearings for testing in LH2 and LO2. A test rig was designed and fabricated specially for the bearing testing. Tests were conducted in LH2 and LO2 on the bearings and on transient shaft support systems under simulated turbopump conditions including the start and shutdown transients confirming the feasibility of using hydrostatic bearings in LH2 and LO2. The design of an existing high pressure LH2 turbopump was modified to incorporate hydrostatic bearings.