摘要:

A mixed pentaerythritol ester composed of 25 mole percent 2-ethylhexanoic and 75 mole percent of isostearic acid substituents was synthesized and characterized. By means of the synthetic and analytical procedures developed, this mixed ester can be prepared in a highly reproducible manner. Oxidation and thermal stabilities, corrosivity, and wetting characteristics are reported. The ester is of interest in instrument and bearing applications where a viscous lubricant having excellent low-temperature properties is required.Presented at the 26th ASLE Annual Meeting in Boston, Massachusetts, May 3—6, 1971

ISSN:0569-8197    

DOI:10.1080/05698197108983238

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

This paper discusses a statistical technique that can be used to investigate a family of lubricants with multivariate data in search of groups or clusters. A computer method for partitioning n lubricants into g groups is described. From this data grouping and perhaps further tests, a lubrication specialist could select lubricants with desirable properties for specific applications. The technique is illustrated on actual data collected on eight different properties of 21 wire-rope lubricants. All trade names of lubricants and names of properties are coded for the discussion.Presented at the 26th ASLE Annual Meeting in Boston, Massachusetts, May 3–6, 1971

ISSN:0569-8197    

DOI:10.1080/05698197108983239

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Two cylinders of identical purely elastic materials are pressed together with parallel axes under the action of a normal force so that a contact strip forms. The cylinders are then shifted with respect to each other, which, under the influence of dry friction, gives rise to Cattaneo's (2) traction distribution with two slip areas. Subsequently they are rolled under the influence of a constant couple, reaching eventually Carter's (3) steady state with one slip area.

ISSN:0569-8197    

DOI:10.1080/05698197108983240

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A pair of ball bearings may produce a mechanical torque at right angles to their spin axis, in addition to their friction torque, which is directed along the spin axis. This paper offers experimental proof that the relative motions of the bearing elements may be controlled so as to insure zero cross-torque.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983241

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The semi-empirical model previously proposed by Hodgson for rarefied gas viscoseals has been modified for multiple thread starts and a scheme developed to solve this modified model for sealing coefficient as well as net leakage performance. This model has been used to predict the performance of a viscoseal over a wide range of gas rarefication conditions. An experimental investigation has been conducted on a multiple grooved two-inch diameter viscoseal, over a wide range of speeds and gas densities. Comparisons are presented between actual viscoseal performance and performance predicted by the modified model. Comparisons include both sealing coefficient and net leakage as functions of the degree of gas rarefication.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983242

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Static friction coefficients were measured for pairs consisting of 20 elemental metals. The 210 friction values were compared against the metallurgical compatibility ratings of the corresponding two phase alloy systems. Soft metals gave higher friction than harder metals, and at the same hardness level there was a steady trend to lower friction in going from like, to compatible, to intermediate, and then to incompatible combinations. The results are interpreted in terms of the surface energy model of friction, and used to derive values for the surface energy of adhesion of metal combinations in terms of their compatibility rating.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference held in Cincinnati, Ohio, October 13–15, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983243

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

An analysis has been carried out of some twelve studies in the literature describing the effect of the metallurgical compatibility of metal pairs on their friction, wear, or adhesion. In each case the rank correlation coefficient was computed between the compatibility and the tribological parameter. The correlation is zero for adhesion tests, and is positive and increases in the order static friction, kinetic friction, and wear. It is hypothesized that the correlation coefficient is highest for wear studies either because they average the influence of the largest number of individual junctions or else because the contribution of surface energy is greatest during the severe conditions of a sliding test.Presented at the 26th ASLE Annual Meeting in Boston, Massachusetts, May 3–6, 1971

ISSN:0569-8197    

DOI:10.1080/05698197108983244

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Optimum performance of some radial lip-type shaft seals requires a combination of properties in the elastomer: mechanical response requirements of the contact edge are different from those of the flex-section. Since this range of behavior is not available in a single elastomer, a “dual-material” oil seal has been designed and developed in which two or more elastomeric compounds are combined so that the product utilizes efficiently the optimum properties of each. One variation of the dual-material concept is a wear-resistant, low-friction material backed by a conventional elastomer. Frictional loss measurements during operation of an oil-seal is related to the degree of lubrication in the contact area, potential temperature build-up, wear rate, and sealing efficiency; and hence, furnishes a rapidly obtainable estimate of service life and long-term performance characteristics. Laboratory data expressing the dependence of the frictional losses (power consumption, W) on lubricant viscosity, T), shaft speed, N, and radial lip load, P—for dual-material seals, and conventional seals—have been rationalized in terms of the theory of lubricated friction:W = ϕ(PrN)(rNηs/P)nwhere r is shaft radius, s is the width of the contact edge, and ϕ and n are experimentally determined constants. The dependence of W on P provides a sensitive test for the degree of lubrication in the contact area.Presented at the 26th ASLE Annual Meeting in Boston, Massachusetts, May 3–6, 1971

ISSN:0569-8197    

DOI:10.1080/05698197108983245

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A pin-on-disk type friction machine was used to investigate the wear of copper under boundary lubrication conditions.

ISSN:0569-8197    

DOI:10.1080/05698197108983246

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Steam turbine efficiency can be improved by large diameter, high speed stages, provided seal leakage and friction, and wheel windage losses can be contained. This paper describes analysis and design of a steam-lubricated seal applied to a single stage experimental turbine designed for improved efficiencies over conventional types. Proper performance of the seal is vital to overall turbine performance. The seal is subjected to surface speeds of approximately 75,000 fpm and up to 100 psi pressure differential. A sectored fluid film seal that uses hydrostatic steam secondary seals was found to be the best candidate configuration. The sectored seal is considered optimum for tracking capability, although there are limitations on the amount of collar nutation permitted. A description of the computerized steady-state and dynamic analyses are described in an appendix.Presented at the 25th ASLE Annual Meeting in Chicago, May 4–8, 1970

ISSN:0569-8197    

DOI:10.1080/05698197108983247

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor