摘要:

Traces of surface contaminants on precision miniature instrument bearings in guidance and other critical systems can greatly contribute to the ultimate failure of such systems. Current solvent-cleaning procedures employed by Navy facilities to prepare bearings for assembly vary with respect to materials and methods, but the specific effects of these variations on the bearing surfaces are unknown. To critically examine these effects, reference surfaces of specially cleaned 52100 and 440C bearing steels were characterized by Auger electron and X-ray photoelectron spectroscopic analysis, as well as by wettability and infrared studies, subjected to standard sequential cleaning cycles and to individual solvents at several Navy facilities, and re-examined by the same techniques. The data indicated that various quantities of hydrocarbon, ester and other residues were deposited on the reference surfaces during the cleaning process. The results are discussed in terms of comparison of the types, levels and probable origins of the contaminants, and their implications regarding bearing life and reliability.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference in Dayton, Ohio, October 16–18, 1979

ISSN:0569-8197    

DOI:10.1080/05698198108983002

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The paper describes studies towards developing lubricant additive technology to improve the fatigue performance of an oil. The extraordinary performance of a particular organic phosphonate antifatigue additive observed in the authors' laboratory and elsewhere is reviewed together with conflicting EHD film thickness studies of this additive reported in the literature. New optical EHD measurements and electron microscope and microprobe studies which define the mechanism by which the additive acts, are presented.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference in Dayton, Ohio, October 16–18, 1979

ISSN:0569-8197    

DOI:10.1080/05698198108983003

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A thin film oxidation (microoxidation) test has been developed to simulate severe liquid phase oxidation in typical lubrication systems. Tributyl phosphate (TBP), tricresyl phosphate (TCP), trixylyl phosphate (TXP) and t-butylphenyl diphenyl phosphate (TBB) have been evaluated and compared. At low rates, oxidation is not limited by oxygen diffusion at the air-liquid interface. Gel permeation chromatography (GPC) has been adapted to the microoxidation test with the phosphate esters to provide a quantitative analysis of the reaction products as a function of molecular weight. The hydrocarbon portion of the phosphate appears to oxidize as the first step. The oxidized material then reacts further to form a product of about twice the molecular weight of the original phosphate. The formation of polymers appears to be a result of condensation through the oxidized hydrocarbon portion of the molecule. There is little evidence of condensation through the phosphate groups to form P-O-P linkages. The P-O-P condensation appears to be a result of thermal reactions of the phosphate esters (1). The oxidative data obtained for these phosphate esters fit the kinetic expression for a pseudo first order reaction. Relative oxidation stability of the phosphate ester is a function of the ease of oxidation if the hydrocarbon structure of the alcohols, from which the ester is prepared.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference in Dayton, Ohio, October 16–18, 1979

ISSN:0569-8197    

DOI:10.1080/05698198108983004

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A falling body viscometer was developed to measure viscosity of lubricants between 10-1to 105Pa.s at high pressures (up to 3 GPa) and temperatures of 20–200°C. The viscometer was incorporated into a variable-support pressure vessel mounted in an O-frame press. A solenoid is used to raise the falling soft iron plunger to its upper position, where it closes a pair of contacts. On deactivating the upper solenoid, the plunger, falls to the lower position to close a second pair of contacts. Fall times are measured by a timer in 0.1s increments. Viscosity of a few fluids, namely a synthetic turbine engine oil, a mineral oil, white gasoline and a 1:1 mixture of the mineral oil and white gasoline were measured to demonstrate capability of the system. For the synthetic turbine engine oil, isoviscous curves for 102, 103and 104Pa.s are presented on a P–T diagram and estimates are made of the viscosity at which dynamic effects can be expected.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference in Dayton, Ohio, October 16–18, 1979

ISSN:0569-8197    

DOI:10.1080/05698198108983005

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The optimum normal force for maximum efficiency of a spinning-traction contact as used in variable ratio drives has been investigated for two fluids of high- and medium-coefficient of traction. Predictions from a thermo-viscoelastic model that the optimum efficiency is slightly higher for the high-traction fluid over the entire range of traction force are supported experimentally. The theoretical optimum normal force is a small constant value plus an amount approximately proportional to the traction force; in qualitative agreement with established industrial practice.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference in Dayton, Ohio, October 16–18, 1979

ISSN:0569-8197    

DOI:10.1080/05698198108983006

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor