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Experiments are described on the frictional behavior of a petroleum oil in the contact zone between a spherical steel roller and a cylindrical one moving in combined rolling and sliding at 23 C, 100 C, and 190 C, and at maximum Hertz contact stresses of up to 390,000 psi. The coefficient of friction is found to decrease with increasing temperature. The results are interpreted on the hypothesis that the frictional force represents the shearing of a film of essentially solidified lubricant at a shear plane of molecular dimensions. 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 Philadelphia, Pennsylvania, April 1961.

The effect of material variables on the fatigue life of AISI 52100 steel in ball bearings is examined. An apparently significant negative correlation with the abundance of certain trace alloying elements has been found. An effect of gas content has not been proven. Some difference in the endurance of bearings tempered for various lengths of time at different temperatures is shown. The most effective means available for obtaining improved fatigue life are certain techniques of vacuum melting. An approximate two-fold increase over catalog fatigue life is obtained by single vacuum melting, and a 7.7-fold increase has been achieved in tests using multiple consumable electrode vacuum remelting. This, in conjunction with previously reported evidence for the existence of a lower limit for fatigue life, suggests the possibility of producing bearings with better than 99.5% reliability at catalog life. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meetin...

Extensions to the theory for the continuous film journal bearing are presented. These analyses are used in conjunction with the results of other analyses to provide design data orf the complete operating range of a full circular journal bearing. 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 Detroit, Michigan, May, 1965.

The boundary friction properties of the lubricated system of steel sliding on lead-base babbitt were investigated as a phase of the Association of American Railroads' sponsored project on freight car hot boxes. A friction pendulum was developed for determining the coefficients of boundary friction as a function of temperature with the specified metals lubricated with various lube oil additive blends. A group of general relationships dealing with additives for the steel-babbitt system was developed. It is concluded that the extreme pressure agents containing sulfur or chlorine are generally unsuited for railroad journal bearing use. Lubricity additives which function by simple physical adsorption were found to be ineffective at moderate or high temperatures existing in railroad operations. Those lubricity additives which chemisorb to metal surfaces and form a close-packed layer were found to be effective antifriction agents. Contributed by the ASLE Technical Committee on Bearings and Bearing Lubrication an...

The sliding mechanisms of unlubricated gold and palladium are described. Transfer, roughening, wear, friction, and contact resistance phenomena involve the same discrete events. With rider-flat geometry, severely Worked transfer particles form a prow-shaped wedge which adheres to the smaller member. Even when rider and flat are different, prow material comes from the larger part. Loss of prow occurs by adhesive weld-back transfer and, to form loose debris, by shearing or fatigue fracture. Friction rises in the early stages of sliding as prows grow. Soon, back transfer increases hardness of the larger member and friction falls to an equilibrium level. Friction also falls when prows are kneaded into rollers and become loose debris. During these stages, wear rate diminishes. Contact resistance noise originates in stick-slip, roller formation, surface hardening, and changing composition at the sliding interface when dissimilar contact metals are involved. Contributed by the ASLE Technical Committee on Lubrica...

Most carbon-type seal materials contain graphitic carbon as the minor constituent. Materials having graphite carbon as the major constituent were studied as possible seal materials at 10,000 feet per minute sliding velocities, in most experiments the temperature of the mating surfaces was 500°F. Carbon materials made graphitic by electro-graphitization were too soft; they gave high wear and high friction. Bodies molded with high-graphite-content materials and made hard by improved molding methods and impregnation gave acceptable friction and wear properties. When a hardenable stainless steel was used, the effect of varied hardness of mating surface on wear of typical carbon was slight. Within a limited range, roughness of mating surface is not important to wear of carbons. Contributed by the ASLE Technical Committee on Seals and Packings and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, April 1957.

Heat transfer data from recent studies of rotating cylinders are utilized in the the heat balance method of predicting oil film temperatures for shaft and plain bearing combinations. Good agreement is obtained between calculated temperatures and experimental values. It is shown that the heat which is dissipated from a rotating shaft may be much greater than that from a stationary shaft and from the bearing housings, and it may be the major path for heat dissipation in certain cases. Contributed by the ASLE Technical Committee on Lubrication Fundamentals and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Cleveland, Ohio, April, 1958.

In an earlier paper it was shown that mineral oils containing high molecular weight polymer would give better lubrication characteristics (lower friction and lower wear in a V-8 automotive engine) than straight mineral oils of the same viscosity. In this paper, the effects of polymer type, molecular weight and concentration are considered. Generally, friction and wear decrease with polymer concentration, leveling off to a “plateau” which is a characteristic of the given polymer. The level depends on both polymer type and molecular weight, the best results being obtained with the lowest molecular weight polymer. The behavior of polymer/oil blends is also sensitive to the presence of polar surfactants. It is concluded that both the bulk properties of oils, such as viscoelasticity, and surface effects are important in accounting for the advantage of polymer-modified oils. Contributed by the ASLE Technical Committee on Engine Lubrication and presented at the Annual Meeting of the American Society of Lubricati...

Two materials, an intermetallic designated LT-2 and a stabilized formulation of zirconium oxide, designated 1027-ZrO2 were tested in rolling friction studies from room to 2500 F. V-groove and circular groove tests were performed with resulting friction forces measured. The friction behaviors were correlated against previously established mathematical models. It was found that these models were adequate to predict observed friction behavior for the 1027-ZrO2 material. The LT-2 material was found to experience a creep behavior which limited the accuracy of the models in the circular groove configuration when load and time at load were sufficient to cause noticeable creep. It is shown in a quantitative manner that the LT-2 creep behavior is sufficient to cause the observed deviation from the circular groove friction model. 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....

Twenty-nine additives were evaluated for their antiwear and extreme pressure properties when incorporated in various percentages in lithium soap-mineral oil greases. The percentages of the principal antiwear and extreme pressure inducing elements: sulfur, chlorine, phosphorus and lead were determined. The most promising ones were further evaluated in commercial greases and in inorganic thickened diester greases. Evaluations were based upon the Four-ball wear and EP, the Falex, and the Timken testers. Results indicate that phosphorus imparts antiwear properties while sulfur, chlorine, and lead, give EP properties to greases. Combinations of additives would enhance both properties. Increase in the additive concentration gave increased values to the results. The type of grease had an effect upon the efficiency of the additive thus indicating the need to fit the additive to the type and intended use of the grease. Contributed by the ASLE Technical Committee on Properties of Lubricants and presented at the Ann...

The experimental check described proved that viscosity measurements on polymer modified oils with rotational and capillary viscometers can be successfully correlated. The rules for this are the same as those used for other non-Newtonian liquids (solutions of high polymers); namely, viscosity vs. the rate of shear at the wall, R. This is valid to at least 106 sec−1. Contributed by the ASLE Technical Committee on Lubrication Fundamentals, and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, April. 1957.

Solutions of aluminum soaps in hydrocarbons, and of certain other polymeric liquids, show normal stress phenomena when they are subjected to shear—the so-called Weissenberg Effect. In the present paper the influence of speed, concentration, temperature, molecular weight of solute and of the type of solvent on these phenomena is investigated. The normal stress is also found to correlate with the viscosity of the system. Although it is known that this remarkable phenomenon is related to the free energy changes—or the elastically stored energy—there is no comprehensive theory as yet which explains it in terms of the molecules taking part in the straining operation. Contributed by the ASLE Technical Committee on Lubrication Fundamentals and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Philadelphia, Pennsylvania, April 1961.

An exact solution is found for the finite fitted journal bearing. Numerical calculations are carried out for an arc of 60° and an arc of 120° for various positions of the bearing. A comparison is made of the load, pressure distribution, and friction force for the finite bearing and the infinite bearing (no side flow). It is concluded that in general the neglect of side flow yields a solution that may be in great error. Contributed by the ASLE Technical Committee on Bearings and Bearings Lubrication and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Buffalo, N.Y., April, 1959. This work was supported in part by the Office of Ordnance Research, U.S. Army.

A critical examination of Constantinescu's theory of turbulent fluid film lubrication has been undertaken. Several of its anomalies were traced to violations of certain well-established basic phenomena in turbulent shear flows. A new approach, which is free of some of these objections, has been made. It holds promise of yielding a more consistent turbulent lubrication theory. Comparison is given on infinitely long bearing with Constantinescu's 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 Chicago, Illinois, May, 1964.

This paper discusses the effect of some lubricant variables and other relevant factors on gear tooth scuffing. Scuffing is defined as any form of scoring or abrasion of the tooth surface due to metal-to-metal contact. The scuff-limited load is defined as the tooth load at which an arbitrary amount of the working tooth area is scuffed. The factors considered include lubricant bulk viscosity, lubricant type and deterioration, test gear and test machine variables, gear speed, the location and rate of lubricant supply, lubricant supply temperature, and the presence of inert gas atmospheres. The results are compared with, and examined in the light of, other published data. Contributed by the ASLE Technical Committee on Gears and Gear Lubrication and presented at the ASLE Gear Symposium held in Chicago, January, 1959. Presented at the ASLE Gear Lubrication Symposium, Chicago, Illinois, January 26 and 27, 1959.

Detailed measurements were made of the growth of the wear crater in high speed tools when cutting AISI 1141 steel, dry and in the presence of a compounded cutting oil, at two speeds. The time-dependence of wear was studied by plotting the maximum cross sectional area of the crater. After a break-in period, wear assumed a constant rate which depended on the speed and the absence or presence of cutting oil. For a given speed, the wear rate for lubricated cutting was half the rate dry. Tool failure was found not to be an abrupt transition from orderly wear to burn-out, but rather a progression from orderly wear to catastrophically high wear without burn-out, and eventually to failure. These phenomena are discussed in their relation to the author's previously proposed theory of cutting tool wear (1). Contributed by the ASLE Technical Committee on Fluids for Metalworking and presented at the Annual Meeting of the American Society of Lubrication Engineers held in New York, April, 1963.

This paper deals with the effects of lubricant compressibility on the pressure profile and total load capacity in a partial journal bearing; pivot pressure as a measure of shoe load capacity; shoe friction characteristics; and optimum shoe clearnace ratios for various speeds. The parameter A is used as an indicator of the compressibility effect of gas in the bearing clearance. Contributed by the ASLE. Technical Committee on Bearings and Bearing Lubrication and presented at the Annual Meeting of the American Society fo Lubrication Engineers held in Chicago, Illinois, May, 1964.

Data are reported for two rotors (1.44 and 5.88 pounds) supported by externally pressurized gas bearings. Comparative plots show that the effective spring rate for synchronous whirl (a function of pressure) also serves to account for the shaft displacement under gravity load and under low-frequency impact loading. Exceptions are noted at the half-speed whirl threshold and at low speed and low pressure. Some explanation is offered for these discrepancies, as well as for observed displacements somewhat in excess of that predicted on the basis of the linear spring, under impact. 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 Detroit, Michigan, May, 1965.

The slider-bearing with the bearing elastic is analyzed for its load carrying characteristics. The deflection of the bearing under load acts to reduce the load capacity by an amount which can be significant as is illustrated by a numerical example. 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 Detroit, Michigan, April 1957.

For the case of physical bonding, the heat of adsorption of a boundary lubricant on a bearing surface has been shown to determine frictional behavior. The theory is here extended to include the effects of temperature and velocity on wear, and corresponding experimental results are presented. The mathematical form of these dependencies is discussed and a characteristic temperature defined and calculated. As a result, a class of very high temperature boundary lubricants is suggested and some further experimental results summarized. Contributed by the ASLE Technical Committee on Properties of Lubricants and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Buffalo, April, 1959.

A theory of anti-squawk additive behavior was formulated based on diffusion and boundary lubricant formation. Friction tests were run with common friction surfaces in a common white paraffin oil containing different anti-squawk additives and analyzed to evaluate the theory. The data indicated dynamic friction was diffusion controlled at any given additive concentration. Additive concentration was not controlling dynamic friction at concentrations above 0.001 moles per liter, although the dynamic frictional behavior of zinc stearate solutions was concentration dependent below 0.001 moles per liter. Static friction data for zinc stearate followed a Langmuir adsorption isotherm. Friction changes caused by boundary lubricants were proportional to the amount of boundary lubricant on the friction surfaces. Contributed by the ASLE Technical Committee on Lubrication Fundamentals and presented at the Annual Meeting of the American Society of Lubrication Engineers held in New York, April, 1963.

The structural and functional components of high temperature lubrication systems are metal assemblies, lubricants and elastomeric seals. How do combinations of these effect each other under the varying conditions of temperature and atmosphere? This question is often presented to the manufacturers of seals and of lubricants. A laboratory method for determining the answer is presented here. This method exposes combinations of lubricant, metal and elastomer to varying atmospheric conditions at a constant temperature. The degrading effects of temperature alone on each component of a lubricating system are known. This work was prepared to show that the proper selection of the sealing system components can prolong the life of the system. Contributed by the ASLE Technical Committee on Seals and Packings and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Cincinnati, Ohio, April 1960.

Resistance to plastic indentation was measured on a series of 52100 bearing steel samples representing a wide range of heat treatments. The samples were subsequently analyzed for austenite content by an X-ray diffraction method. Within a limited hardness range definite positive correlation was found between austenite content and indentation sensitivity. This correlation was seen to improve further when austenitizing temperature was fixed, indicating that at a fixed hardness level, factors other than austenite content also influence the plastic indentation resistance of rolling element bearing steels. 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 St. Louis, Missouri, May 1962.

A theoretical study was made to determine the influence of lubricant supply rate on the performance of the 360° journal bearing for L/D = 1. The results are presented in chart form to facilitate their application to analysis and design. 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 at St. Louis, Missouri, May 1962.

It is now well known that certain types of cemented carbides give excellent results when used to cut cast irons but poor results when used to cut steels and vice versa. This relative ability of a given tool material to perform well when cutting a given workpiece material is referred to here as compatibility. Ceramic metal cutting tools have been in use in machining metals such a short time that it is not yet generally known on which materials these tools can be used to best advantage. In this report the performance of ceramic and cemented carbide tools is compared when machining a wide variety of metals. It is found that there are certain metals for which either the surface chemical or thermal characteristics of ceramic tools are particularly advantageous. The report is concluded by a table which lists a large number of ferrous and nonferrous metals in order of decreasing compatibility with aluminum oxide tools. Contributed by the ASLE Technical Committee on Metal-working Fluids and presented at the Annua...

Some secondary effects which can influence the operation of self-acting gas-lubricated bearings are analyzed, i.e., effect of the inertia forces, thermal effects, turbulence, and effect of the molecular character of the flow. In order to point out their qualitative influence as well as the conditions in which such influences can be important, the case of infinitely long bearings is considered, but for the computation of quantitative effects, the real case of finite bearings is used. 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 Chicago, Illinois, May, 1964.

This paper deals with recent work applicable to the problems of high-temperature lubrication carried out in the Laboratory of Physics and Chemistry of Solids, University of Cambridge, England. Three main aspects are considered (a) friction of lamellar solids, (b) lubrication from the gas phase (c) frictional properties of hard metals at high temperatures. Contributed by the ASLE Technical Committee on Lubrication Fundamentals and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Buffalo, New York, April 1959.

The lubrication requirements of the Mercury Rankine Silent Compact Auxiliary Power (SCAP) system are presented and the types of journal and thrust bearings suitable for the application are reviewed. Mercury lubricated hybrid bearings have been successfully developed for the turboalternator that are capable of a dry start, and operation in a vertical orientation and at elevated temperatures up to 400 F. Performance characteristics of these bearings operating at mean Reynolds numbers of approximately 4,500 are presented. 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 Detroit, Michigan, May, 1965.

A radiotracer method of investigation was developed to study metallic contact phenomena in rolling contacts. It consists of activating one rolling element and running it against inactive parts onto Which active material is deposited during operation. The transferred activity is Quantitatively determined by calibrated autoradiography. Exploratory tests on cylindrical roller bearings show the location of high pressure areas in the contacts in agreement with elasticity theory. The tests performed so far do not permit the definite determination that the deposited activity is transferred by micro-welding in direct metallic contact. (The possibility exists that it is deposited out of contaminated lubricant.) A simple modification of the method is outlined to overcome this ambiguity. 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 St. Louis, Missouri, May 1962.

The conventional model of orthogonal cutting with type 2 chip is modified to include the effect of deformation of the work-piece at the immediate vicinity of the tool-tip. The cutting velocity condition for optimal force of deformation is examined in the light of two alternate criteria: recrystallization temperature and melting temperature. It is shown that a critical cutting velocity exists. Furthermore, it is concluded, in part, that proper metallurgical treatment and/or preheating the work-piece (hot machining) will improve cutting. Contributed by the ASLE Technical Committee on Lubrication Fundamentals and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Pittsburgh, Pa. April 1956.

The behavior of the oil in a cavitation region is studied. Boundary conditions of the pressure distribution at the inlet and at the outlet border of such a region are given. Calculation of the power loss in a cavitated zone is demonstrated. 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 Cincinnati, Ohio, April 1960.

The friction-wear characteristics in air and in vacuum are reported for a group of composites that have recently been developed for ultra high vacuum service. They have demonstrated their ability to carry loads of 1400 psi with low self-wear and negligible wear of the surfaces against which they slide. These composites, made up of polytetrafluoroethylene (PTFE) and a solid lubricant distributed throughout a metal matrix, have been utilized as self-lubricating components in ball bearings operating in environments that conventional lubricants cannot tolerate. These environments include high vacuum (10−8 torr) and temperatures from -180 to 400 F. 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 New York, April, 1963.

Externally pressurized thrust collar gas-bearings with several supply holes are investigated theoretically. The gas supply holes are spaced circumferentially and communicate, directly with the film without feeding into recesses. A complex potential function which satisfies the boundary conditions of the bearing is found, and the pressure distribution, quantity of flow, and load capacity are calculated for the two cases where there are or are not radial grooves between the holes. The theory is applicable for any number of gas supply holes. 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 New York, April. 1963.

In the past the results obtained from humidity cabinet corrosion tests have been useful for comparing one protective material with another, but of little value for predicting the protective life of any given material under atmospheric exposure conditions. A corrosivity factor, arbitrarily developed, has been found invalid. A method has been developed from experimental data by which the humidity cabinet life of a lubricant may be used to predict its protective life on steel when exposed to the atmosphere. This method is expressed mathematically as a function of temperature, humidity, and protective life (time). It is applicable for world-wide use by using local temperature and humidity data for the location under consideration. The same general equation appears to be applicable for any lubricant. Each lubricant has its own constants, which must be determined from experimental data. The constants for two lubricants have been determined. Contributed by the ASLE Technical Committee on Properties of Lubricants...

The test method used to guide the development of carbon-graphites suitable for main shaft seals in jet aircraft is described. A simplified seal assembly was used. Rubbing speeds up to 16,700 fpm and face loadings to 18 psi were attained. Details on the test apparatus and the sample preparation methods are included. Wear rates, air leakage rates past the seal face, and seal temperature rise due to friction were measured. All tests described in this paper were conducted in air without added lubrication of any type. Typical data for four carbon-graphites are included to show the effects of carbon type, face pressure, rubbing speed, and mating face material. Contributed by the ASLE Technical Committee on Seals and Packings and presented at the Annual Meeting of the American Society of Lubrication Engineers held in St. Louis, Missouri, May 1962.

Lumped and distributed parameter analyses of the inherently compensated gas journal bearing are developed for small eccentricity ratios. Curves are presented for static and dynamic gas film forces and for bearing gas flow requirements. Experimental results are compared with the theories for the case of plane vibration. 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 Chicago, Illinois, May 1964.

This paper describes experimental measurements of the conditions occurring in the conjunctive region of two lubricated cylindrical disks which roll or roll and slide on their peripheral surfaces under load. The results of these measurements are compared with those of the recent elastohydrodynamic theory, including thermal effects. The measured quantities include lubricant film pressure distribution, surface temperature distribution, and the shape and thickness of the lubricant film, all measured in the direction of rolling. The results suggest several improvements and modifications of the thermal elastohydrodynamic theory including an improved analysis of the inlet region and modification of the lubricant rheological model to include effects of shear or time dependence. 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 Detroit, Michigan, May, 1965.

Various criteria have been used in metal cutting operations to study the effectiveness of cutting fluids; for example, tool-life, wear, temperature and forces; work surface finish; and chip deformation. In each case a number of measurement methods may be employed. This paper describes two very simple means of measurement which have been found useful in cutting fluid research. The first is based on measurement of work surface finish in the direction of cut by determining the amount of pencil lead abraded by the surface under controlled conditions. The second is based on measurement of chip deformation by electrical resistance determination of chips from a known depth of cut. Contributed by the ASLE Technical Committee on Metal Working Fluids and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Buffalo, New York, April 1959.

Polymers in automotive oils permit a practical compromise between low- and high-temperature viscosity requirements. Oils containing polymer have low temperature (0 F) viscosities 10% to 50% greater than predicted by the ASTM equation (D-341-43). This disadvantage is outweighed by their favorable balance between engine friction and oil consumption. They have high shear viscosities 20% to 40% less than their conventional viscosities, with corresponding friction horsepower reductions over similar non-polymer oils of 10% or more with no penalty in consumption. Correlation of friction horsepower with viscosity suggests that the controlling shear rates are 750,000 sec−1 or more. Dispersancy is an added property built into some of the polymeric additives. Low duty field tests demonstrate the effectiveness of this dispersancy in redistributing the “sludge balance” to keep the engine contaminants in the oil and filter and not in the working parts of the engine. Contributed by the ASLE Technical Committee on Proper...

The results of an experimental investigation of an externally pressurized, porous wall, nonrotating journal bearing that used air as a lubricant are compared with a previously published analysis and found to be in good general agreement, provided the eject of surface roughness is included in the determination of the clearance. 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 Detroit, Michigan, May, 1965.

The work of several authors on the pressure depression effect in externally pressurized gas-lubricated bearings is presented, and improved mathematical formulas and experimental evidence are introduced. The use of the free surface, water table analogue as an aid in the visualization and study of the pressure-depression effect is presented. Good qualitative agreement was found between this analogue and the available experimental data. 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 Chicago, Illinois, May, 1964.

A study has been made of and friction phenomena associated with rubbing surfaces (primarily molybdenum) in sodium environments. Operating conditions include vacuum or argon environments and specimen temperatures from 80 to 1300 F. Sliding speeds were about one half inch per minute and contact stresses were about 100,000 psi. Sliding specimens consisted of a ball sliding on a flat rectangle. Wear and friction behavior were found to be influenced by surfaces films which were modified by the presence of liquid sodium. Contributed by the ASLE Technical Committee on Bearings and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Philadelphia. Pennsylvania. April 1961.

A numerical scheme, suitable for digital computer use, is presented for the solution of the elasto-hydrodynamic problem. The variation of viscosity with pressure, compressibility, and, of course, surface deformations are included in this analysis. The method is applicable over a wide range of loads—from the lightly loaded situation where there is simple hydrodynamic lubrication up to the heavily loaded cases where the pressure distribution is closely related to the Hertzian pressure distribution for the contact of unlubricated surfaces. A series of solutions are presented which show the importance of the various effects and a study is made showing the transition region between the hydrodynamic and Hertzian pressure distributions. 1 Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Carnegie Institute of Technology. Contributed by the ASLE Technical Committee on Gears and Gear Lubricants and presented at the Annual Meeting of the American Society of Lubrication E...

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.

The experimental and analytical literature is reviewed briefly and is drawn upon to provide solutions for the interactions of weak pressure flows with a strong Couette flow, as would be experienced in turbulent film bearings. In the pertinent derivations, care has been taken to avoid known pitfalls in the application of mixing-length theory. Insofar as is possible, the results are shown to be in accord with reported experimental measurements. The areas of uncertainty in these analyses are areas where further experimental measurements are called 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 Chicago, Illinois, May, 1964.

This paper presents some of the theoretical predictions and experimental results for the steady-state characteristics of a gas-lubricated, pivoted-pad journal bearing of finite length. An analytical expression for the prediction of load-carrying capacity for these bearings is developed from numerical computer solutions. Sample calculations are presented to show how the theoretical data may be utilized in the design of an actual pivoted-pad bearing. Improvements over previous approximate theories are discussed. 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 New York, April, 1963.

This paper presents the theoretical development and experimental verification of a simplified technique for the design of externally pressurized gas lubricated bearings. The general procedure is to establish an equivalent rectangular bearing which is the performance replica of an arbitrary gas bearing configuration. The resulting equivalent bearing has the same load support, clearance, area, source pressure, entrance losses, and mass flow as the arbitrary bearing which is analyzed. In accomplishing this end, the general rectangular bearing is analyzed, a consistent criterion of equivalence is defined, and theoretical analyses are compared to experimental data. 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 St. Louis, Missouri, May 1962.

The preparation and preliminary evaluation of a number of trimeric and tetrameric bis (α, α, ω-tri H-polyfluoroalkyl) phosphonitrilates, mixed substituted trimeric and tetrameric (phenyl-α, α, ω-tri H-polyfluoroalkyl) phosphonitrilates, and mixed substituted trimeric and tetrameric (substituted phenyl-α, α, ω-tri H-polyfluoroalkyl) phosphonitrilates is described. Many products have wide liquid ranges with pour points ranging down to —55 F. They also have high compression ignition ratios and relatively high spontaneous ignition temperatures. Good wear, and compatibility with rubber are other favorable properties. In order to obtain hydrolytically stable products, new synthesis and purification methods were developed. The compounds are promising candidates for potential use as fire-resistant hydraulic fluids and lubricants. Contributed by the ASLE Technical Committee on Properties of Lubricants and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Chicago, Illinois May...