Showing papers in "Tribology Transactions in 1966"
TL;DR: In this article, the empirical relationship between the rate of adhesive wear and the ratio of load to hardness has been extended to consider the presence of a lubricant film on the surface.
Abstract: The empirical relationship between the rate of adhesive wear and the ratio of load to hardness has been extended to consider the presence of a lubricant film on the surface. The expression contains two parameters, one of which is specific to characteristics of the lubricant and the other specific to characteristics of the sliding metal couple. A model is developed which considers the heat of adsorption as the controlling factor in the effectiveness of the boundary lubricant. The wear rate of a copper pin sliding against a steel disk with n-hexadecane as lubricant was determined as a function of load, sliding velocity, and temperature. Confirmation of the model is observed and the calculated heat of adsorption is 11.5 kcal per mole. The estimated wear coefficient for that portion of the real area of contact which is metal-metal is about 0.2. This suggests that the probability will be near unity that a wear partiole will be formed. Presented as an American Society of Lubrication Engineers paper at the Lubri...
96 citations
TL;DR: A new class of high-temperature fluids, designated PR-143, which are capable of use in the range of −50 to −700 F, is discussed in this article.
Abstract: A new class of high-temperature fluids, designated PR-143, which are capable of use in the range of −50 to −700 F, is discussed. These fluorinated materials do not sludge or tar on high-temperature exposure, even in the presence of air. The fluids are being tested in hydraulic systems, as gas turbine engine oils and as base fluids for high-temperature greases (designated PR-240). Properties and test results related to these applications are given. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
90 citations
TL;DR: In this article, an analytical method based on elastohydrodynamic lubrication theory was proposed to predict bearing cage speed, and therefore the extent of skidding, under any condition of radial load and shaft speed.
Abstract: Skidding which occurs in high speed roller bearings frequently causes wear and incipient failure of bearing inner ring and roller surfaces. To eliminate skidding, aircraft gas turbine designers, historically, have employed out-of-round outer rings and other preloading devices. Prior to testing of the full-scale bearings at engine speeds, however, the designers have not, heretofore, been able to determine (a) the extent of skidding which occurs and (b) the effectiveness of means employed to eliminate skidding. The analytical method which is presented by this discussion is based upon recently developed elastohydrodynamic lubrication theory and can be used in lieu of expensive testing procedures to adequately predict bearing cage speed, and therefore the extent of skidding, under any condition of radial load and shaft speed. Moreover, the analysis can be used to determine how much radial preloading or outer ring out-of-roundness is necessary to minimize skidding. The analytical data of this study are compare...
88 citations
TL;DR: In this article, a study of chemical reaction between iron surfaces and various representative extreme pressure (EP) agents, such as chlorine type, sulfur type, Zn-dithiophosphate type, and the mixture of sulfur and chlorine type EP agents, by using the hot wire method is presented.
Abstract: The work to be described in this paper, is a study of chemical reaction between iron surfaces and various representative extreme pressure (EP) agents, such as chlorine type, sulfur type, Zn-dithiophosphate type, and the mixture of sulfur and chlorine type EP agents, by using the hot wire method. It has been observed that the corrosion rate of iron follows the parabolic law or the cubic law. The parabolic law can be explained by the diffusion mechanism of corrosion. In order to explain the cubic law, the corrosion retarding action of a barrier film has been assumed. From the X-ray analysis of reaction products, the complexity of corrosion process has been revealed. Zinc-diisobutyldithiophosphate has shown the characteristic behavior in the corrosion process, showing retardation against the corrosion. With a binary additives system, the joint reaction of sulfur and chlorine compounds on iron could not be satisfactorily supported in the scope of this study. Some interesting considerations are given for the c...
74 citations
TL;DR: The importance of surface temperature in disk and gear lubrication is well established so the methods to measure it need study as mentioned in this paper, and it is shown that a trailing thermocouple is liable to error.
Abstract: The importance of surface temperature in disk and gear lubrication is well established so the methods to measure it need study. It is shown that a trailing thermocouple is liable to error. The oil film thickness in an Amsler disk machine as measured by voltage discharge is found to agree excellently with theory, providing the correct surface temperatures are used to obtain the oil viscosity. Next the effects of speed, load, viscosity, and surface finish on friction are studied. An empirical relation relating these measurements, as well as all other published data, is presented. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
73 citations
TL;DR: Self-lubricating composite materials prepared by vacuum impregnating nickel-chromium alloy with barium fluoride-calcium fluoride eutectic composition are described in this paper.
Abstract: Self-lubricating composite materials prepared by vacuum impregnating nickel-chromium alloy with barium fluoride-calcium fluoride eutectic composition
42 citations
TL;DR: In this paper, X-ray fluorescence was used to detect the start of surface coating formation on steel balls with oil blends containing seven commercial additives, and the results indicated that in situ polymerization may be an important phenomenon occurring on rubbing surfaces.
Abstract: Dynamic friction and static immersion tests in which oil temperature was varied and dynamic friction tests in which load was varied have been run on steel balls with oil blends containing seven commercial additives. Analyses of the ball surfaces by X-ray fluorescence have shown that significant surface coating formation is initiated at calculated surface temperatures of from 250 to 350 F for most of the additives studied. Although the surface coating “thickness” generally increased with temperature, the rate of increase was generally different for the static and dynamic tests. Both surface temperature and mechanical shearing appear to influence the reactions responsible for the surface coatings. Used oil analyses showed that base oil oxidation, additive decomposition, and, in some cases, sludge formation became detectible at temperatures corresponding to the start of significant surface coating formation. The results suggest that in situ polymerization may be an important phenomenon occurring on rubbing s...
38 citations
BP1
TL;DR: In this paper, the strong affinity of the surfaces of the solid lubricants and cast iron for paraffinic hydrocarbons was investigated and it was shown that the strong attachment of oil molecules to the surface of the dispersed solid reduces its EP effectiveness.
Abstract: Several layered solids, which are effective solid lubricants, have a strong affinity for methylene groups. This leads to preferential adsorption on the solids of those paraffinic molecules that can form the maximum number of contacts with the surface and with each other. Thus the strength of adsorption of mineral oils increases with their average molecular weight. The strong affinity of the surfaces of the solid lubricants and cast iron for paraffinic hydrocarbon is expected to influence their load-carrying capacity, in that it should be higher for the oleophilic sliding surfaces than for surfaces such as those of plain steel, which are devoid of this property. So far, however, this has not been confirmed experimentally. For MoS2 dispersed in mineral oils, indications have been obtained that the strong attachment of oil molecules to the surfaces of the dispersed solid reduces its EP effectiveness. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Fra...
37 citations
TL;DR: Friction and wear of hexagonal metals and alloys as related to crystal structure and lattice parameters in vacuum was studied in this paper, where the authors considered the wear of alloys and hexagonal metal alloys.
Abstract: Friction and wear of hexagonal metals and alloys as related to crystal structure and lattice parameters in vacuum
37 citations
TL;DR: A new class of stable aromatic fluids structurally related to the polyphenyl ethers are described in this article, which are characterized by resistance to degradation by oxidation, heat, ionizing radiation, and hydrolysis.
Abstract: A new class of stable aromatic fluids structurally related to the polyphenyl ethers are described. Designated as aromatic C-ethers, they are characterized by resistance to degradation by oxidation, heat, ionizing radiation, and hydrolysis. They are oxidatively stable in the temperature range of 500–600 F and have thermal decomposition temperatures above 700 F. Acceptable damage levels are observed at radiation dosage rates up to 107 rads at 375 F. The C-ethers offer considerable promise as high-temperature lubricants with outstanding gear load-carrying capacities. The fluids are compatible with many elastomers and most engineering materials and are essentially nontoxic. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
20 citations
TL;DR: In this paper, a set of nonlinear, coupled partial differential equations is developed to include the effects of the solid particles in a liquid base lubricant, and the results obtained in actual bearing tests with a universal bearing test machine are compared to the results of numerical analysis.
Abstract: This investigation was undertaken for tile purpose of extending the design theories for hydrodynamic bearings to include the effects of solid particles in a liquid base lubricant. A set of nonlinear, coupled partial differential equations is developed to include the effects of the solid particles. Solutions of the mathematical model by numerical analysis are compared to the results obtained in actual bearing tests with a universal bearing test machine. Increased friction from the solids is shown to be limited to a certain range of operation such that at Sommerfeld numbers above or below this range there is only a slight increase in the friction above that obtained with the liquid alone. Good agreement between the theoretical solutions and experimental values was obtained by using experimentally determined particle shear strengths. Contributed by the ASLE Committee on Lubricant Fundamentals and presented at the Annual Meeting of American Society of Lubrication Engineers, held in Pittsburgh, Pennsylvania, M...
TL;DR: In this article, it was shown that vapor lubrication applies to lamellar solids only when relatively high specific forces are acting between the layers, and not for all other solids studied.
Abstract: Friction measurements have been made on a series of layer lattice compounds selected from a number of different crystal systems. Experiments in ultrahigh vacuum confirm the vapor lubrication mechanism for natural graphite, pyrolytic graphite, and boron nitride. For all other lamellar solids studied there was no evidence that vapor lubrication played a role in the sliding mechanism. It is likely that vapor lubrication applies to lamellar solids only when relatively high specific forces are acting between the layers. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
TL;DR: In this article, an iterative method is developed for computing quasi-stationary temperatures in a large body due to a moving heat source on the surface, considering temperature dependence of thermal properties.
Abstract: An iterative method is developed for computing quasi-stationary temperatures in a large body due to a moving heat source on the surface, considering temperature dependence of thermal properties. Thermal properties of materials are classified into six categories. For surface temperatures encountered in the moving heat source problem for which the Peclet number is large, the function (fg) −1/2 is identified as the indicator whether it is necessary to consider temperature dependence of the relevant thermal properties. The temperature dependence of density times specific heat and thermal conductivity in dimension-less form are given by f and g, respectively. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
TL;DR: In this article, the effect of imperfections of the stationary bearing component becomes a junction of their location relative to the pressure producing region of the bearing and creates a difficult problem in predicting characteristic performance results.
Abstract: In fabricating gas bearing components, it is necessary to establish allowable tolerances on out-of-roundness, taper and surface finish of the parts. Several evaluations of the effects of these variable on bearing performance characteristics were conducted in order to determine reasonable bearing tolerances. It was found that, generally, variations in diameter of the rotating member can be averaged out for predicting performance. Unfortunately, the effect of imperfections of the stationary bearing component becomes a junction of their location relative to the pressure producing region of the bearing and creates a difficult problem in predicting characteristic performance results. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Pittsburgh, Pa., May 3–5, 1966.
TL;DR: In this article, a new family of lubricants, hybrids between silicones and hydrocarbons, is introduced and characterized, and physical properties of representative members of the series are presented and their exceptional lubricating ability is shown.
Abstract: A new family of lubricants, hybrids between silicones and hydrocarbons, is introduced and characterized. The physical properties of representative members of the series are presented and their exceptional lubricating ability is shown. A possible mechanism for such lubricity is postulated. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
TL;DR: In this article, the effect of varying viscosity and density with temperature has been taken into account by solving simultaneously the Reynolds Equation and the Energy Equation for a square pad (L/B = 1) with a digital computer.
Abstract: The classical case in lubrication of two flat rectangular surfaces has been solved to account for the variable properties of the lubricant The effect of varying viscosity and density with temperature has been taken into account by solving simultaneously the Reynolds Equation and the Energy Equation for a square pad (L/B = 1) with a digital computer The case of two insulated plates is used; no heat conduction is allowed The solutions are compared with the classical theory which assumes the lubricant to have constant properties Curves showing the pressure and temperature distributions are presented Design curves are given for the performance of fixed pad bearings, pivoted pad bearings with central pivots as well as optimum pivots, and parallel surfaces A criterion for estimating the significance of heat effects is mentioned Contributed to the American Society of Lubrication Engineers by the author
TL;DR: In this article, the introduction of a petrolatum containing solid powders, metallic and non-metallic, leads to an increase in adhesion between steel surfaces at low solid content.
Abstract: The introduction of a petrolatum containing solid powders, metallic and non-metallic, leads to an increase in adhesion between steel surfaces at low solid content. At higher concentrations the adhesion in most cases is reduced. All the lubricant mixtures increase the fatigue life of the specimens, but there is little correlation between adhesion and fatigue life. High adhesion gives a lower increase, and unbroken specimens are associated with a low adhesion. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
TL;DR: The use of an elastic orifice in a test bearing demonstrates an increase in bearing stiffness over a conventional fixed orifice when compared at a common operating point as discussed by the authors, and increased bearing stiffness may allow the use of these bearings in applications formerly restricted to pressurized liquid and rolling contact bearings.
Abstract: The merit of using an elastic orifice compensator in externally pressurized gas bearings is examined. The use of an elastic orifice in a test bearing demonstrates an increase in bearing stiffness over a conventional fixed orifice when compared at a common operating point. This attribute should be welcome wherever externally pressurized bearings are used. In addition, increased bearing stiffness may allow the use of these bearings in applications formerly restricted to pressurized liquid and rolling contact bearings. Information is included to allow construction of working models of these orifices and duplication of experimental results. Contributed to the American Society of Lubrication Engineers by the author.
TL;DR: In this article, hydrogenated oligomers of octene-1 offered the optimum balance of high viscosity index, low pour point and excellent stability for polyolefin fluids.
Abstract: Polyolefin fluids covering a wide viscosity range have been produced in quantities sufficient for direct comparison with petroleum oils and with existing synthetic-lubricants. Preliminary studies, conducted to choose the best synthesis route, revealed that hydrogenated oligomers of octene-1 offered the optimum balance of high viscosity index, low pour point and excellent stability. Further work with alpha-olefin blends, aimed at the most economical approach, now shows that essentially equivalent results can be obtained with the proper blend of C6 to C10 olefins. Such fluids when produced in large volumes could compete economically with present synthetics. Tests on two candidate products—an automatic transmission fluid for high-temperature service and a jet engine lubricant—demonstrate product capabilities under conditions which cannot be satisfied with conventional petroleum oils. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., O...
TL;DR: In this paper, it is argued that oil nozzle position and depth of oil impingement are important variables and analytically shown by using the Ryder gears how these important variables could contribute to the load-carrying ability of oils and how these contributions could affect the Ryder ratings of oils.
Abstract: Variations and inconsistencies in the ratings of rocket engine lubricating oils on the Ryder Gear Tester prompted an analytical investigation into the mechanism of lubrication. It is considered that gears are lubricated on the disengaging side primarily to rapidly dissipate frictional heat. Based on this consideration, it is contended that oil nozzle position and depth of oil impingement are important variables. It is analytically shown by using the Ryder gears how these important variables could contribute to the load-carrying ability of oils and how these contributions could affect the Ryder ratings of oils. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
TL;DR: In this article, an experimental program has been conducted to compare the effective lives of ball bearings operating in vacuum with various types of MoS2 solid films, and with a special high vacuum oil, as lubricants.
Abstract: An experimental program has been conducted to compare the effective lives of ball bearings operating in vacuum with various types of MoS2 solid films, and with a special high vacuum oil, as lubricants. The test bearings were size 205 bearings running at 30 rpm under a ten-pound radial load. Two particular combinations were also evaluated in oscillating motion tests. Torque was used as the criterion for failure. Prior to test the bearings were subjected to a 2100-pound static load to simulate launch loading. The results of these tests showed that most of the solid film-lubricated bearings were effective for the first several hundred hours, then gave high and erratic torque values as the result of debris being formed by wear of the lubricant film. A sodium-silicate bonded solid lubricant film, which contained MoS2 and graphite, was found to be particularly promising in both rotation and oscillation. One particularly significant result of this work was the finding that the oil-lubricated bearings showed a su...
TL;DR: In this paper, the effect of three mineral base oils on roller bearing fatigue life has been studied, using a specially controlled group of 45mm bore cylindrical roller bearings, and the results indicate that base oil stock affects bearing performance.
Abstract: The effect of three mineral base oils on roller bearing fatigue life has been studied. Life performance tests were conducted, using a specially controlled group of 45-mm bore cylindrical roller bearings. The results indicate that base oil stock affects bearing performance. Of the highly naphthenic, naphthenic, and paraffinic mineral oils studied, bearings lubricated with the latter achieved superior lives. The use of an oxidation inhibitor in the naphthenic base oil provided an improvement in the life performance equivalent to that obtained with the paraffinic base lubricant. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco Calif., October 18–20, 1965.
TL;DR: In this paper, a program was conducted to evaluate materials that could be used as lubricants in rolling-contact bearings operating in a liquid hydrogen environment at DN values up to 4 million mm-rpm.
Abstract: A program was conducted to evaluate materials that could be used as lubricants in rolling-contact bearings operating in a liquid hydrogen environment at DN values up to 4 million mm-rpm. A unique ball and plate test apparatus was used to test twenty candidate lubricant materials selected for screening in the initial phase of the program. The ball-plate tester eliminated the use of test bearings in the initial material screening phase where the important factor was to evaluate the lubricants and bearing materials without the confounding effect of other bearing parameters. No tests were conducted in a nuclear radiation field; however, consideration was given to such an environment in the selection of the candidate materials. The lubricant investigation described herein resulted in the selection of four materials, bronze-filled fluorocarbon, bronze-filled polyimide, Ag-WSe2-polyimide and Ag-MoS2, for further evaluation in actual bearing tests. These materials show promise of providing a significant increase ...
TL;DR: In this article, five low-temperature fluids (dimethyl silicone, a silicate ester, a branched chain chloro-fluorocarbon, a cyclic fluorinated ether and a fluorinated polyether) were evaluated for use as the fluid in a single pass, gas actuated hydraulic system capable of operation from −150 to 275 F.
Abstract: Five fluids (a dimethyl silicone, a silicate ester, a branched chain chloro-fluorocarbon, a cyclic fluorinated ether and a fluorinated polyether) were evaluated for use as the fluid in a single pass, gas actuated hydraulic system capable of operation from −150 to 275 F. Important physical and chemical properties, including thermal stability, lubricity, viscosity, pour, low-temperature characteristics and flash point, were determined. Specific heat, thermal conductivity and density values were compiled from manufacturer's data. The fluorinated polyether was chosen as the most suitable fluid for the low-temperature system. The phenyl silicones were determined to be the only elastomers suitable for use in dynamic and static seals of the system. Several typical phenyl silicone compounds were tested for compatibility with the five low-temperature fluids. Leakage tests were run in a static seal fixture with several of the fluids. A proprietory phenyl silicone compound was chosen as the best material for use wit...
TL;DR: In this article, a laboratory method for simulating the wear experienced by misaligned splines is described, and typical experimental data are presented, including the use of matched spline specimens subjected to relative oscillatory motion simulating angular misalignment, under the influence of an applied torque.
Abstract: The development of a laboratory method for simulating the wear experienced by misaligned splines is described, and typical experimental data are presented. The experimental program involves the use of matched spline specimens subjected to relative oscillatory motion simulating angular misalignment, under the influence of an applied torque. The test specimens are maintained at 250 F, either with or without lubrication, in the presence of dry air, moist air, JP-5 fuel, or JP-6 fuel. The extent of spline wear is quantitatively monitored on a continuous basis. The experimental results obtained with above environments and seven different greases reveal significantly different wear mitigation characteristics for the various greases. Moreover, the influences of the spline environments differ for the different greases. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
TL;DR: In this paper, the design, calibration, and use of a PRL high pressure capillary viscometer for the range of 0 to 10,000 psig was presented, and the effects of drainage, kinetic energy correction, alignment, surface tension, bulk modulus of the glass capillary, density of the pressurizing gas, and solubility at the gas-liquid interface were discussed.
Abstract: The design, calibration, and use of a PRL high pressure capillary viscometer for the range of 0 to 10,000 psig is presented. The effects of drainage, kinetic energy correction, alignment, surface tension, bulk modulus of the glass capillary, density of the pressurizing gas, and solubility at the gas-liquid interface are discussed. Internal repeatability, as well as correlation with the ASME pressure-viscosity project falling ball viscometer, is shown. Viscosity-pressure data for several fluids and the effect of dissolved gas on the pressure-viscosity properties are demonstrated. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.
TL;DR: In this article, a new class of silicone copolymers containing both trifluoropropyl and halophenyl substitution was described, which can cover a temperature span of −100 F to 650 F. Data are included showing that this combination improves both low and heavy load anti-wear properties for steel.
Abstract: Chlorophenyl substituted silicones have better lubricating properties than lightly phenylated methyl silicones with similar physical properties. The best load-carrying and anti-wear properties are obtained with fluorosilicones at some loss in low-temperature properties. This paper describes a new class of silicone copolymers containing both trifluoropropyl and halophenyl substitution which can cover a temperature span of −100 F to 650 F. Data are included showing that this combination improves both low and heavy load anti-wear properties for steel. Physical, friction and wear, and stability data are given describing these properties as a function of the type, and amount of halogen on the phenyl as well as with varying ratios of trifluoropropyl to halophenyl substitution. Differences in lubricating performances and mechanisms for various halogenated groups are discussed to explain the improvements noted for the combination of halophenyl with trifluoropropyl groups. Final formulation of a potential wide tem...
TL;DR: In this paper, the fundamentals of lubricant flow and distribution within wicking materials were determined experimentally and applied to the design of wick-lubricating systems for small sleeve bearings.
Abstract: The fundamentals of lubricant flow and distribution within wicking materials were determined experimentally. Application to the design of wick-lubricating systems for small sleeve bearings is discussed. Contributed to the American Society of Lubrication Engineers by the author.
TL;DR: An analysis of a system of hydrostatic bearings used to support a rigid structure subjected to either specified loads or movements is described, and results of sample problems are shown in this article, where the governing equations are developed, considering generalized system supply circuitry and arbitrary selection of fixed type compensating elements for each bearing.
Abstract: An analysis of a system of hydrostatic bearings used to support a rigid structure subjected to either specified loads or movements is described, and results of sample problems are shown. The governing equations are developed, considering generalized system supply circuitry and arbitrary selection of fixed type compensating elements for each bearing. The equations have been programmed for solution on a high-speed digital computer. The methods of solution and conceptual flow chart of the program are described. From specified loads (or alternatively displacements) of a point on the body chosen as the origin, individual bearing performance parameters, resultant body displacements (or alternatively loads), and the hydraulic system parameters are determined. Contributed by the ASLE Committee on Lubricant Fundamentals and presented at the Annual Meeting of American Society of Lubrication Engineers, held in Pittsburgh, Pennsylvania, May 3–5, 1966.
TL;DR: In this article, the externally pressurized rectangular pad with multiple supply holes is analyzed theoretically by use of complex potential theory, and an appropriate potential function which satisfies the boundary conditions, is found by using infinite arrays of infinite sources and sinks.
Abstract: The externally pressurized rectangular pad with multiple supply holes are analyzed theoretically by use of complex potential theory. An appropriate potential function, which satisfies the boundary conditions, is found by using infinite arrays of infinite sources and sinks. Then, the pressure distribution can be obtained theoretically, which leads to the determination of load capacity and flow. Results are given for both incompressible and compressible fluids. Experimental results coincide very well with theory concerning pressure distribution and load capacity if secondary effects owing to the compressibility of the fluid and pressure loss at supply holes is accounted for. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Pittsburgh, Pa., May 3–5, 1966.