Developments in Supercleaning and Boundary Lubrication for Gas-Bearing Gyros Related to Surface Phenomena

British aerodynamic gas-bearing gyros of the highest precision for use in Naval equipment are required to have long durability of low starting friction for the brief periods of rubbing contact before the rotor becomes gas-borne. Start failures in service have caused the Navy Department to initiate a two-phase programme of investigation and research into the problem. The first phase, intended to enable production to continue and reasonable performance to be obtained, is reported in references [1, 2]. The second phase, described herein, has been of a more fundamental nature and has been intended to amend hitherto empirical processes to a sound scientific basis and to gain understanding of bearing surface behavior. The paper describes trials and results of experiments carried out jointly by Admiralty Compass Observatory and Shell Research Ltd. on various aspects of bearing cleaning, boundary-lubricant behavior, and bearing surface materials. Glow discharge cleaning, examined by radiotracer technique, has been found to be very much more efficient than organic solvents, as well as permitting a big reduction in process time. Proposals for a simplified and more effective cleaning process and for boundary lubrication with a fatty acid are given. Examinations of surface films by friction machine, radiotracer techniques, electron diffraction, and ellipsometry have established that chemical bonding occurs between bearing surfaces and boundary lubricant and have enabled film thicknesses of molecular proportions and molecular orientations to be determined. Preliminary work is reported on the effects of processes described on ceramic bearing materials.