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Techniques for investigation of friction and wear in aerospace bearings
382
I.ITEKATUNE
ANI)
Reproducible wear results were obtained which represent a survey of the available seal face materials. Critical Aspects in Bearing Fatigue Testing. J. F. Moult, Lubrication Eng., 19 (IQ) (x963) 503~51 I ; 12 figs., discussion. Present laboratory practice compares the results of full-scale bearing fatigue tests to establish improvements in design, material and lubrication. Since all these factors have significant influence on performance, fatigue tests must be controlled for valid comparison. Results of interrelated material and lubricant tests are presented to demonstrate the magnitude of variation in performance. It is suggested that individual laboratories employ a standard bearing sample and standard lubricant as a baseline for comparative tests. It is proposed that bearing and lubricant standards be established for cross-comparison of laboratory test results on an industry-wide basis. A Review of Techniques for Investigation of Friction and Wear in Aerospace Ball and Roller Bearings. L. C. Lipp and E. N. Klemgard, Lubrication Eng., 19 (I 2) (1963) 4g5-5oz ; I fig., 4 tables, 23 refs. Mechanisms by which friction and wear occur in aerospace ball and roller bearings are extremely complicated and it is impossible to study all of them simultaneously. The paper reviews analytical and experimental methods for isolation and investigation of twenty-one parameters of importance in friction and wear of aerospace ball and roller bearings when operating under conditions of - 65 to + 1500~ F, 10-9 mm Hg pressure, and variable loads and speeds. The use of infra-red analysis, emission spectroscopy, mass spectroscopy, metallography, electron microscopy, highspeed photography, radioactive isotopes, radiation pyrometers, and friction measuring oscilloscopes are instrumental in the study of these friction and wear parameters. Application of a thin adherent lubricant coating to the ball and roller bearing surfaces is a well-known problem and six possible methods by which this may be accomplished are covered. Techniques for Investigation of Friction and Wear in Aerospace Bearings. H. E. Staph et al., Interim Report 1962-1963, Wright-Patterson A.F.B., Ohio, Flight Dynamics Lab. ; South-west Research Institute, 1963, 148 pp., 65 refs. Sci. and Tech. Aerospace Repts.,
I (zo)
(1963)
1604.
Instrumentation techniques have been developed which may be applied to the stud] of several parameters believed to contribute to friction and wear in rolling-element bear-
CllHKEST
EVENTS
ings. Measurements are made on the bearings during operation. Ultimate goal for instruO.j'I' t0 1 ,jOO' 1; mentation applicability is bearing temperature, 10-s’ torr vacuum and 24,000 r.p.m. speed. The principal instrument for performing the measurements is a pIat-form called a “cage follower”, which rotatrs in a plane alongside and parallel to that of the bearing and in synchronism with the cage. Cage-mounted transducers for tempcrature and strain may be connected to the cage follower by fine wires. X.C. or d.c. transducer signals may be telemetered from the moving shaft through coupling transformers. The USC of the cage follower to measure ball spin is described. Ball and cage temperature measurement by infrared techniques has been studied and shows feasibility. Material transfer occurring during bearing operation is measured on the doubly-curved bearing surfaces by preformed autoradiographs and scintillation counting. J,itcrature on the effects of the presence of electric, and magnetic fields on wear in rolling element bearings is summarized. Recent Development of the M.A.N. Marine Diesel Engine. (A lecture) E. Sorenson and F. Schmidt, at the Institute of Marine Engineers, London, January, 1964. For a short version see Sci. Lubricatio?z, 16 (1964)
25.
Laboratory Engine Testing of Marine Diesel Cylinder Lubricants. (A lecture) A. J. S. Baker and R. T. Davies. For a short version see Sri. Lubrication, rj (1963)
19.
Application of Rolling Element Coastdown Techniques to the Determination of Lubricant Properties. S. F. Murray, U.S. Office of Naval Research, 1963, 73 pp. (Order no. AD 402-308, O.T.S., U.S. Dept. of Commerce, Washington, D.C., 20230, price 7j cents.) Modifications of experimental techniques currently being used in Navy research on elastohydrodynamic lubrication are described in this report. Earlier research had established a technique for studying elastohydrodynamic lubrication by measuring the coastdown characteristics of lubricated instrument-size ball bearings. It was found that the straightchain dimethyl silicones have exceptionally long coastdown times as compared with polyalkylene glycols or petroleum oils of comparable bulk viscosity, particularly in the high viscosity ranges. Oils of more reasonable bulk viscosity are now being investigated. The Ultimate Scuffing Load of Gear Lubricants. Parts 1 and 2. (in German) U’~~ar,7
(rg64) 373-383
I.ITEKATUNE
ANI)
Reproducible wear results were obtained which represent a survey of the available seal face materials. Critical Aspects in Bearing Fatigue Testing. J. F. Moult, Lubrication Eng., 19 (IQ) (x963) 503~51 I ; 12 figs., discussion. Present laboratory practice compares the results of full-scale bearing fatigue tests to establish improvements in design, material and lubrication. Since all these factors have significant influence on performance, fatigue tests must be controlled for valid comparison. Results of interrelated material and lubricant tests are presented to demonstrate the magnitude of variation in performance. It is suggested that individual laboratories employ a standard bearing sample and standard lubricant as a baseline for comparative tests. It is proposed that bearing and lubricant standards be established for cross-comparison of laboratory test results on an industry-wide basis. A Review of Techniques for Investigation of Friction and Wear in Aerospace Ball and Roller Bearings. L. C. Lipp and E. N. Klemgard, Lubrication Eng., 19 (I 2) (1963) 4g5-5oz ; I fig., 4 tables, 23 refs. Mechanisms by which friction and wear occur in aerospace ball and roller bearings are extremely complicated and it is impossible to study all of them simultaneously. The paper reviews analytical and experimental methods for isolation and investigation of twenty-one parameters of importance in friction and wear of aerospace ball and roller bearings when operating under conditions of - 65 to + 1500~ F, 10-9 mm Hg pressure, and variable loads and speeds. The use of infra-red analysis, emission spectroscopy, mass spectroscopy, metallography, electron microscopy, highspeed photography, radioactive isotopes, radiation pyrometers, and friction measuring oscilloscopes are instrumental in the study of these friction and wear parameters. Application of a thin adherent lubricant coating to the ball and roller bearing surfaces is a well-known problem and six possible methods by which this may be accomplished are covered. Techniques for Investigation of Friction and Wear in Aerospace Bearings. H. E. Staph et al., Interim Report 1962-1963, Wright-Patterson A.F.B., Ohio, Flight Dynamics Lab. ; South-west Research Institute, 1963, 148 pp., 65 refs. Sci. and Tech. Aerospace Repts.,
I (zo)
(1963)
1604.
Instrumentation techniques have been developed which may be applied to the stud] of several parameters believed to contribute to friction and wear in rolling-element bear-
CllHKEST
EVENTS
ings. Measurements are made on the bearings during operation. Ultimate goal for instruO.j'I' t0 1 ,jOO' 1; mentation applicability is bearing temperature, 10-s’ torr vacuum and 24,000 r.p.m. speed. The principal instrument for performing the measurements is a pIat-form called a “cage follower”, which rotatrs in a plane alongside and parallel to that of the bearing and in synchronism with the cage. Cage-mounted transducers for tempcrature and strain may be connected to the cage follower by fine wires. X.C. or d.c. transducer signals may be telemetered from the moving shaft through coupling transformers. The USC of the cage follower to measure ball spin is described. Ball and cage temperature measurement by infrared techniques has been studied and shows feasibility. Material transfer occurring during bearing operation is measured on the doubly-curved bearing surfaces by preformed autoradiographs and scintillation counting. J,itcrature on the effects of the presence of electric, and magnetic fields on wear in rolling element bearings is summarized. Recent Development of the M.A.N. Marine Diesel Engine. (A lecture) E. Sorenson and F. Schmidt, at the Institute of Marine Engineers, London, January, 1964. For a short version see Sci. Lubricatio?z, 16 (1964)
25.
Laboratory Engine Testing of Marine Diesel Cylinder Lubricants. (A lecture) A. J. S. Baker and R. T. Davies. For a short version see Sri. Lubrication, rj (1963)
19.
Application of Rolling Element Coastdown Techniques to the Determination of Lubricant Properties. S. F. Murray, U.S. Office of Naval Research, 1963, 73 pp. (Order no. AD 402-308, O.T.S., U.S. Dept. of Commerce, Washington, D.C., 20230, price 7j cents.) Modifications of experimental techniques currently being used in Navy research on elastohydrodynamic lubrication are described in this report. Earlier research had established a technique for studying elastohydrodynamic lubrication by measuring the coastdown characteristics of lubricated instrument-size ball bearings. It was found that the straightchain dimethyl silicones have exceptionally long coastdown times as compared with polyalkylene glycols or petroleum oils of comparable bulk viscosity, particularly in the high viscosity ranges. Oils of more reasonable bulk viscosity are now being investigated. The Ultimate Scuffing Load of Gear Lubricants. Parts 1 and 2. (in German) U’~~ar,7
(rg64) 373-383