Accession Number : ADA305068

Title :   Evaluation of Two Polyimides and of an Improved Liner Retention Design for Self-Lubricating Bushings,

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

Personal Author(s) : Sliney, Harold E.

PDF Url : ADA305068

Report Date : 24 OCT 1984

Pagination or Media Count : 17

Abstract : Two different polyimide polymers were studied; in addition, the effectiveness of a design feature to improve retention of the self-lubricating composite liners under high load was evaluated. The basic bearing design consisted of a molded layer of chopped graphite-fiber-reinforced-polyimide (GFRPI) composite bonded to the bore of a steel bushing. The friction, wear, and the load carrying ability of the bushings were determined in oscillating tests at 25C, 260C, and 315C at radial unit loads up to 260 MPa. Friction coefficients were typically 0.15 to 0.25. Bushings with liners containing a new partially fluorinated polymer were functional, but had a lower load capacity and higher wear rates than those containing a more conventional, high temperature polyimide. The liner retention design feature reduced the tendency of the liners to crack and work out of the contact zone under high oscillating loads.

Descriptors :   *FIBER REINFORCED COMPOSITES, *BUSHINGS, *POLYIMIDE RESINS, POLYMERS, HIGH TEMPERATURE, CRACKING(FRACTURING), CRACKS, CARBON FIBERS, STEEL, LININGS, WEAR, DYNAMIC LOADS, FAILURE(MECHANICS), FRICTION, THERMAL CYCLING TESTS, THERMAL STRESSES, CYCLIC LOADS, GRAPHITE EPOXY COMPOSITES, RADIAL STRESS, JOURNAL BEARINGS, SELF LUBRICATION.

Subject Categories : Laminates and Composite Materials
      Plastics
      Couplers, Fasteners, and Joints

Distribution Statement : APPROVED FOR PUBLIC RELEASE