摘要:

Experiments carried out in a laboratory multicylinder gasoline engine with mineral oil lubricants containing radioactive (P32-labeled) zinc di(C6)alkyl dithiophosphate show that strongly attached films are formed by this compound on many of the rubbing metal surfaces of the engine. Results are presented on the effects of chemical treatments on the radioactivity of the metal surfaces and on a technique by which the films are removed and assayed with a Geiger counter. On the basis of radioactivity per unit of geometrical contact area, most of the active parts were the highly stressed components of the valve train mechanism. These included the cams, valve lifter faces, push rod ends, rocker arm bearing areas and valve stem ends. The activity of the valve lifter faces was found to be influenced by (a) lifter metallurgy, (b) degree of break-in and (c) the presence of a detergent-inhibitor additive in the lubricant. Autoradiographs show that practically all the activity on a cam surface is localized at the cam nose—the region of greatest stress, of greatest surface damage and where metal transfer is known to occur. It is estimated that the films found on the cams and valve lifters are several molecular layers thick. The data support the idea that the action of zinc dialkyl dithiophosphate in reducing valve train wear in automotive engines involves the formation of phosphorus-containing protective films by chemical reaction with the rubbing metal surfaces. In addition, the results of this study suggest that this radiotracer method may be useful for locating critical areas of boundary lubrication in other mechanical devices.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Los Angeles, Calif., October, 1958.

ISSN:0569-8197    

DOI:10.1080/05698195908972361

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

The demand for large quantities of liquefied gases has necessitated the development of liquefaction turbines and pumping systems. These developments have required studies of bearings and bearing materials suitable for operation in liquid hydrogen and other liquefied gases. The apparatus used to measure frictional torque, wear, and to make life tests on bearings submerged in liquefied gases is described. The information concerning ball bearings obtained from this equipment and some bearing information obtained from an apparatus designed to make basic pump studies is presented. Frictional torque data, wear data, and pictures showing a few of the test ball bearings are included.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Los Angeles, Calif., October, 1958.

ISSN:0569-8197    

DOI:10.1080/05698195908972362

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

The rolling contact fatigue spin rig was used to study the interrelation of fiber orientation and fatigue. In both balls and specially oriented races, a concentration of fatigue failures was observed in regions with the highest angle of intersection of fiber flow lines with the surface. In one race specimen fewer failures per unit area were obtained with increasing distance from the billet axis so that variations in cleanliness in the race may have been important. Further tests are necessary to determine the actual importance of cleanliness. In races, increase in fiber orientation angle also resulted in poorer fatigue life. The fatigue life of M-1 tool steel balls decreased with increasing temperature when using a synthetic lubricant, and was low with dry powder lubricants at 450°F, possibly due to the lubricant particles acting as mechanical stress raisers within the contact zone.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Los Angeles, Calif., October, 1958.

ISSN:0569-8197    

DOI:10.1080/05698195908972363

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

Modern aircraft are pushing bearing temperatures beyond the limits of standard steels and lubricating fluids. Newer materials are introducing serious uncertainties into design life calculations. So many parameters and such a spread of statistical phenomena are involved that a “bench” type tester is essential as a substitute for full scale bearing tests to screen material-lube combinations. A high temperature tester has been built, and several months of testing at 400°F have emphasized the magnitude of the problem by showing that (a) the state of oxidation of diesters is a significant factor with several materials, (b) life can vary appreciably between apparently similar heats of steel, (c) hardness is an important factor that needs much more study, (d) standard cleanliness measurements do not seem to be sufficient to establish relative quality.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Los Angeles, Calif., October 1958.

ISSN:0569-8197    

DOI:10.1080/05698195908972364

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

The effect of vacuum melting has been under investigation by the author's company for several years. Fatigue testing has been conducted on races and balls in full-sized bearings, so that the results can be interpreted directly into bearing performance.

ISSN:0569-8197    

DOI:10.1080/05698195908972365

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

Reynolds' equation for a 120° partial journal bearing of the clearance type having an L/D ratio of 1 is solved numerically to determine the effect of positioning circumferentially the line of action of the load at various points along the bearing arc. The influence of the load position (α/β) on film thickness, eccentricity, journal position, friction, flow, temperature rise, and maximum film pressure is investigated and performance curves given. It is shown that the position of the load has a significant effect on bearing performance.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Los Angeles, Calif., October, 1958.

ISSN:0569-8197    

DOI:10.1080/05698195908972366

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor