Accession Number : ADA306097

Title :   Evaluation of Journal Bearings of Various Materials in Low-Viscosity Fluids, Liquid Nitrogen, and Liquid Oxygen.

Descriptive Note : Technical note,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON DC

Personal Author(s) : Cunningham, Robert E. ; Anderson, William J.

PDF Url : ADA306097

Report Date : NOV 1964

Pagination or Media Count : 27

Abstract : An experimental investigation was undertaken to determine the feasibility of operating journal bearings in cryogenic liquids at surface speeds comparable to those of current generation oxidant turbopumps. Tests were conducted with 1.0- and 1.5-inch-diameter bearings. Results from tests in liquid nitrogen and liquid oxygen were generally poor due to the difficulty of maintaining a hydrodynamic film. It is hypothesized that boiling of the cryogenic fluids may have occurred within the bearing clearance area, creating a two-phase-flow condition. A sharp decrease in the effective viscosity and in the bearing load-carrying capacity resulted. The best performance from tests with journal bearings fully immersed in liquid-oxygen was obtained with (1) fused polytetrafluoroethylene (PTFE) coated wrought-nickel-copper alloy sleeves, (2) a 15-percent glass-filled PTFE liner on steel, and (3) PTFE plus lead in sintered bronze. These materials were capable of sustaining moderate loads at surface speeds to 76 feet per second for a short duration. Liquid-oxygen pressure fed to the bearings at approximately 5 pounds per square inch gage above atmospheric pressure (boiling point,- 302 deg F) did not improve performance over the tests fully immersed at atmospheric pressure. jg p3

Descriptors :   *FLUIDS, *LIQUID NITROGEN, *VISCOSITY, *LOW RATE, *LIQUID OXYGEN, *JOURNAL BEARINGS, TEST AND EVALUATION, VELOCITY, POLYMERS, LOADS(FORCES), FILMS, STEEL, SURFACES, LININGS, ORGANIC COMPOUNDS, OXIDIZERS, BAROMETRIC PRESSURE, HYDRODYNAMICS, CRYOGENICS, SINTERING, BOILING POINT, BEARING CAPACITY, TURBOPUMPS, BRONZE.

Subject Categories : Machinery and Tools
      Inorganic Chemistry
      Organic Chemistry
      Polymer Chemistry
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE