Accession Number : ADA317259

Title :   Engine Hybrid Ceramic Bearings.

Descriptive Note : Final rept. 23 May 92-23 Nov 94,

Corporate Author : GE AIRCRAFT ENGINES CINCINNATI OH

Personal Author(s) : Rhoads, M. ; Bashyam, M.

PDF Url : ADA317259

Report Date : NOV 1994

Pagination or Media Count : 118

Abstract : The objective of this program was the development of additional performance data and condition-monitoring techniques for silicon nitride (Si3N4) bearings. Induced-defect testing was performed to assess the ability of silicon nitride balls to withstand the high shock loads experienced during the growth of a race spall. The defect was placed in the outer ring of a hybrid bearing. Conclusions were made as to the survivability of ceramic balls under such severe conditions. High-speed thermal performance was compared between an all-steel bearing, a hybrid with the same internal geometry, and a hybrid with tightened internal geometry to lower the hertzian contact stress. Conclusions were made as to whether the hybrid bearings offer any improvement in thermal performance over an all-steel bearing. A condition-monitoring methodology was developed for early detection of an impending bearing failure. A technique was developed to find both metallic and ceramic debris from bearings. A monitoring device was developed, constructed, and demonstrated.

Descriptors :   *ROLLER BEARINGS, *SILICON NITRIDES, *BALL BEARINGS, TEST AND EVALUATION, RISK, FATIGUE LIFE, MONITORING, AIRCRAFT ENGINES, HIGH TEMPERATURE, HIGH VELOCITY, FRACTURE(MECHANICS), CERAMIC MATERIALS, GAS TURBINES, DEFECTS(MATERIALS), IMPACT SHOCK, INFRARED DETECTORS, FAILURE(MECHANICS), SHOCK TESTS, THERMAL STRESSES, THERMAL SHOCK, CRANKSHAFTS.

Subject Categories : Ceramics, Refractories and Glass
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE