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Experimental Study of Load Carrying Capacity of Point Contacts at Zero Entrainment VelocityA capacitance technique was used to monitor the film thickness separating two steel balls while subjecting the ball-ball contact to highly stressed, zero entrainment velocity conditions. Tests were performed in a nitrogen atmosphere and utilized 52100 steel balls and a polyalphaolefin lubricant. Capacitance to film thickness accuracy was verified under pure rolling conditions using established EHL theory. Zero entrainment velocity tests were performed at sliding speeds from 6.0 to 10.0 m/s and for sustained amounts of time to 28.8 min. The protective lubricant film separating the specimens at zero entrainment velocity had a film thickness between 0.10 to 0.14 microns (4 to 6 micro in.), which corresponded to a k value of 4. The formation of an immobile surface film formed by lubricant entrapment is discussed as an explanation of the load carrying capacity at zero entrainment velocity conditions, relevant to the ball-ball contacts occurring in retainerless ball bearings.
Document ID
19980237013
Acquisition Source
Legacy CDMS
Document Type
Technical Memorandum (TM)
Authors
Shogin, B. A. (Case Western Reserve Univ. Cleveland, OH United States)
Jones, W. R., Jr. (NASA Lewis Research Center Cleveland, OH United States)
Kingsbury, E. P. (IRC, Inc. Walpole, MA United States)
Jansen, M. J. (AYT Corp. Brook Park, OH United States)
Prahl, J. M. (Case Western Reserve Univ. Cleveland, OH United States)
Date Acquired
September 6, 2013
Publication Date
October 1, 1998
Subject Category
Fluid Mechanics And Heat Transfer
Report/Patent Number
E-11369
NASA/TM-1998-208650
NAS 1.15:208650
Meeting Information
Meeting: AUSTRIB ''98
Location: Brisbane
Country: Australia
Start Date: December 6, 1998
End Date: December 9, 1998
Sponsors: Institution of Engineers
Funding Number(s)
PROJECT: RTOP 274-00-00
CONTRACT_GRANT: NCC3-409
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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