Accession Number : ADA307371

Title :   Dynamic Load Capacities of Graphite-Fiber - Polyimide Composites in Oscillating Plain Bearings to 340 deg C (650 deg F).

Descriptive Note : Technical note,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s) : Sliney, Harold E. ; Jacobson, Thomas P. ; Munson, Harold E.

PDF Url : ADA307371

Report Date : JAN 1975

Pagination or Media Count : 18

Abstract : Load capacities were determined for plain spherical bearings with self lubricating spherical elements of graphite-fiber-reinforced-polyimide, and for plain cylindrical bearings with thin- wall liners of the composite in the bearing bores. Composites consisted of a 1-to-1 weight ratio of graphite fibers and polyimide. Oscillation was at an amplitude of + or - 15 deg at a frequency of 1 hertz. Bearings with composite ball material had a load capacity of approximately 69 MN/sq m (10,000 psi) at room temperature and 25 MN/sq m (3600 psi) at 340 C (650 F). Bearings with thin-wall composite liners had much higher load capacities of 280 MN/sq m (40,000 psi) at room temperature and 240 MN/sq m (35,000 psi) at 320 C (600 F). Friction coefficients Were in the range of 0.12 to 0.19. The addition of 10 wt. % graphite fluoride solid lubricant to the composition of the thin-wall liners reduced friction coefficients into the range of 0.10 to 0.12.

Descriptors :   *FIBER REINFORCED COMPOSITES, *SPACE SHUTTLES, *BEARINGS, *POLYIMIDE PLASTICS, *SELF LUBRICATION, POLYMERS, GRAPHITE, FRACTURE(MECHANICS), DYNAMIC LOADS, FAILURE(MECHANICS), FRICTION, AERODYNAMIC HEATING, SLIDING FRICTION.

Subject Categories : Laminates and Composite Materials
      Plastics
      Machinery and Tools
      Manned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE