Bearing Tests of Lubricant Additive Formulation and Pretreatment Processes.
Abstract
It has been found that a new cleaning process, based on an aqueous alkaline detergent and implemented to eliminate the use of ozone-depleting chemicals from ball bearing processing, removes the protective layer formed on the bearing surface by a widely used anti-wear additive (tricresyl phosphate, or TCP) pretreatment. Accelerated laboratory bearing tests have been performed to investigate the effects on bearing wear life and performance of the additive pretreatment versus using oil formulated with the additive. These issues are of particular importance because bearings for several spacecraft mechanisms are currently cleaned with the new process; the bearing tests were conducted with a lubricant used in numerous momentum transfer wheels, Coray 100. The results of the wear tests and the post-test analyses have demonstrated that maximum benefit of TCP is obtained when the additive is formulated with the lubricant. Wear lives of the test bearings lubricated with formulated oil were found to improve by a factor of 15 over those lubricated with the base oil. Pretreated bearings had only a slight improvement in wear life (1.5X) when compared to untreated bearings in tests with unformulated oil. Profilometry performed on the flat counterfaces after testing revealed significant wear on bearings that operated without formulated oil and little wear on bearings tested with formulated oil. Based on these test results, little or no harmful effect is expected to arise from the use of the aqueous alkaline detergent cleaning method, provided that the bearings are lubricated with an oil containing an anti-wear additive. jg p3
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 20, 1995
- Accession Number
- ADA305551
Entities
People
- C. G. Kalogeras
- S. V. Didziulis
Organizations
- The Aerospace Corporation