摘要:

As an extension of earlier work, a systematic study was made of the changes in the antioxidant capacity and infrared spectra of zinc dialkylthiophosphate in model systems and in a fully formulated lubricant aged in laboratory and fleet tests. The reaction of peroxy radicals with a zinc dialkyldithiophosphate in the model systems results in a decay of the P = S absorbance to approximately 40 percent of its initial value. The P=S absorbance is linearly related to the remaining antioxidant capacity of the solutions. For the fully formulated lubricant containing a second ldquo;ashless” antioxidant, the P=S decays to a much lower value approaching zero as the antioxidant capacity approaches a value of about 20 percent of its initial value. A study of the behavior of a zinc dialkyldithiophosphate in admixtures with hindered phenol reveals that the zinc dialkyldithiophosphate was not protected from antioxidant reactions by the hindered phenol, a result which is consistent with results obtained with the fully formulated lubricant.Presented at the 34th Annual Meeting in St. Louis, Missouri April 30–May 3, 1979

ISSN:0569-8197    

DOI:10.1080/05698198008982962

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Earlier model systems studies have shown that the products of the antioxidant reactions of a zinc Dialkyldithiophosphate (ZDTP) with peroxy radicals are ineffective as antiwear agents. Now a similar study has been carried out with a fully formulated synthetic hydrocarbon/ester engine oil aged in fleet tests. The results are consistent with those reported earlier and indicate that the previous conclusion can be extended to a fully formulated lubricant in service. It was found that base stocks containing esters can exhibit increased wear upon addition of ZDTP. However, this can be suppressed by other oil additives.

ISSN:0569-8197    

DOI:10.1080/05698198008982963

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The paper commences with a description of a technique used to obtain the shear strength properties of thin (ca 100nm) solid polymeric films. The effect of velocity in this sliding experiment is rationalized in terms of the contact time in which a load is applied to an element of material and the shear strain rate in the film.

ISSN:0569-8197    

DOI:10.1080/05698198008982964

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Determination of leakage flow and separation force of gas turbine engine mainshaft seals and similar devices represents a unique application of the quasi-one-dimensional compressible flow equation (6), (10). This nonlinear equation has been solved numerically by various authors, for nozzle, diffuser, duct, seal, and similar applications. It has been found, however, that the solution methods reported in the literature may be inoperative for seals with small clearance-to-length ratio, or when the seal is appreciably distorted. This difficulty is caused by a boundary layer type behavior (12) resulting from a singularity in the vicinity of sonic flow, i.e., when the flow Mach number approaches unity.

ISSN:0569-8197    

DOI:10.1080/05698198008982965

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

This study presents a comprehensive methodology for evaluating seal designs or applications.

ISSN:0569-8197    

DOI:10.1080/05698198008982966

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Boundary lubricating characteristics, thermal stability and oxidation-corrosion stability were determined for a fluorinated polyether and a perfluoropolyether triazine. A ball-on-disk apparatus, a tensimeter and oxidation-corrosion apparatus were used. Results were compared to data for a polyphenyl ether and a C-ether. The polyether and triazine yielded better boundary lubricating characteristics than either the polyphenyl ether or C-ether. The polyphenyl ether had the greatest thermal stability (443°C) while the other fluids had stabilities in the range 389° to 397°C. Oxidation-corrosion results indicated the following order of stabilities: perfluoropolyether triazine > polyphenylether > C-ether > fluorinated polyether.Presented at the 34th Annual Meeting in St. Louis, Missouri, April 30–May 3, 1979

ISSN:0569-8197    

DOI:10.1080/05698198008982967

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A surface pressure/temperature transducer has been used to measure contact zone pressure and temperature distribution between a pair of steel disks. In addition, traction/slip curves have been generated for the same conditions. Data for oils representing a broad range of lubricant types are presented. They are(1) Synthetic paraffinic lubricant(2) Traction fluid (synthetic hydrocarbon)(3) Polyphenyl ether(4) MIL-L-23699 lubricant.

ISSN:0569-8197    

DOI:10.1080/05698198008982968

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The wear of low-density polyethylene on steel was studied as a function of the roughness of the steel surface and the sliding speed. The wear rate was found to increase as the speed and roughness increased. The mechanism of wear on surfaces with an Raroughness of 0.065 μm was shown by SEM photos to be film formation and subsequent film breakup and debris formation. On surfaces with an Raof 1.16 μm roughness, wear was primarily abrasive as evidenced by large wear particles and minimal film formation. The effect of sliding speed was to accelerate the film formation or abrasive wear rather than alter the wear mechanism. The tendency for film formation was correlated with the surface parameters of skewness and kurtosis.Presented at the 34th Annual Meeting in St. Louis, Missouri, April 30–May 3, 1979

ISSN:0569-8197    

DOI:10.1080/05698198008982969

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A face seal model is analyzed, taking into account both diametral tilt and coning of the primary seal ring. The Reynolds equation for incompressible fluid is solved analytically using the narrow seal approximation. The solution covers a wide range of tilt and coning angles, from complete alignment to touch-down. Seal performance like axial force, tilting moment, axial and angular stiffness, and leakage are analyzed. It is found that interaction between diametral tilt and coning strongly affects seal performance.Presented at the 34th Annual Meeting in St. Louis, Missouri, April 30–May 3, 1979

ISSN:0569-8197    

DOI:10.1080/05698198008982970

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A scanning Auger microprobe (SAM) investigation was performed to determine the spatial distribution of species produced during boundary lubrication at a steel-on-steel interface. Some correlations were made with the severity of wear as determined by a modified cup-block ASTM-EP lubricant test. Tested extreme-pressure (EP) additives include zinc di-isodecyldithiophosphate (ZDP), hexadecyl diethyldithiocarbamate (HDDC), and benzyl disulfide (BD).Presented at the 34th Annual Meeting in St. Louis, Missouri, April 30–May 3, 1979

ISSN:0569-8197    

DOI:10.1080/05698198008982971

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor